Scholars@Duke
David R. Smith

David R. Smith

James B. Duke Distinguished Professor of Electrical and Computer Engineering
Electrical and Computer Engineering
drsmith@duke.edu
Box 90291, Durham, NC 27708-0291
2527 CIEMAS Building, Durham, NC 27708

Selected Publications

Europium doped Gd2O3 and GdBO3 scintillators for thermal neutron detection

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · March 1, 2023 Neutron detectors used in various applications in nuclear security and nuclear safety are mostly based on the 3He technology. Unfortunately, in the last few years, the market of 3He has encountered huge problems in matching the supply and demand leading to ... Full text Cite

Determination of Energy Resolution for YSO:Ce Detector Modelled with FLUKA Code

Conference 2022 IEEE NSS/MIC RTSD - IEEE Nuclear Science Symposium, Medical Imaging Conference and Room Temperature Semiconductor Detector Conference · January 1, 2022 In this paper, a 5×5×5 mm3 YSO:Ce scintillator detector was modelled with FLUKA code, and calculations for the determination of energy resolution are reported using energies of 59.5, 81, 356, and 661.7 keV. We measured the energy resolution of the scintill ... Full text Cite

Optimised Lambda Architecture for Monitoring Scientific Infrastructure

Journal Article IEEE Transactions on Parallel and Distributed Systems · June 1, 2021 Within scientific infrastructuscientists execute millions of computational jobs daily, resulting in the movement of petabytes of data over the heterogeneous infrastructure. Monitoring the computing and user activities over such a complex infrastructure is ... Full text Cite

Performance of four CVD diamond radiation sensors at high temperature

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · April 1, 2020 Ionising radiation detectors based on wide band-gap materials have the potential to operate at temperatures higher than 200°C. Such detectors are important in applications such as monitoring near nuclear reactors and in deep oil and gas well borehole loggi ... Full text Cite

Validation of gyrokinetic simulations of a National Spherical Torus eXperiment H-mode plasma and comparisons with a high-k scattering synthetic diagnostic

Journal Article Plasma Physics and Controlled Fusion · October 15, 2019 A new extensive validation study performed for a modest-beta National Spherical Torus eXperiment (NSTX) neutral beam injection-heated H-mode discharge predicts that electron thermal transport can be entirely explained by short-wavelength electron-scale tur ... Full text Cite

A portable test-bench for real-time radiation damage measurements in scintillating and wavelength-shifting fibres

Conference 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2019 · October 1, 2019 A portable test-bench has been developed to enable the real-time measurement of radiation-induced absorption in scintillating and wavelength-shifting fibres. Such fibres are typically used in the readout of fibre calorimeters or scintillating tiles such as ... Full text Cite

Experimental observation of electron-scale turbulence evolution across the L-H transition in the National Spherical Torus Experiment

Journal Article Nuclear Fusion · August 6, 2019 Electron-scale turbulence (for 3 k s12) was measured during the L-H transition in the National Spherical Torus Experiment (NSTX) (Ono et al 2000 Nucl. Fusion 40 557) using a coherent microwave scattering system. The measurements were carried out at a radia ... Full text Cite

NSTX/NSTX-U theory, modeling and analysis results

Journal Article Nuclear Fusion · June 5, 2019 The mission of the spherical tokamak NSTX-U is to explore the physics that drives core and pedestal transport and stability at high-β and low collisionality, as part of the development of the spherical tokamak (ST) concept towards a compact, low-cost ST-ba ... Full text Cite

Strain Sensing with Metamaterial Composites

Journal Article Advanced Optical Materials · May 3, 2019 Mapping strain fields in visually opaque structural composites—for which failure is often sudden, irreparable, and even catastrophic—requires techniques to locate and record regions of stress, fatigue, and incipient failure. Many composite materials are tr ... Full text Cite

Variational design method for dipole-based volumetric artificial media.

Journal Article Optics express · March 2019 A fundamental challenge has plagued computer-generated volumetric holography since its inception: design methods are available only in the perturbative limit, but this poses serious limitations on efficiency and the amount of multiplexing achievable. Given ... Full text Cite

Phaseless radar coincidence imaging with a MIMO SAR platform

Journal Article Remote Sensing · March 1, 2019 The correlation-based synthetic aperture radar imaging technique, termed radar coincidence imaging, is extended to a fully multistatic multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) configuration. Within this framework, we explore two ... Full text Cite

Out-of-plane computer-generated multicolor waveguide holography

Journal Article Optica · February 20, 2019 Multicolor waveguide holography remains a challenge due to its inherent design complexity, compounded by the limited low-loss materials available in the optical range as well as challenges in nanofabrication. In this study, we first propose and experimenta ... Full text Cite

Enhancing Capacity of Spatial Multiplexing Systems Using Reconfigurable Cavity-Backed Metasurface Antennas in Clustered MIMO Channels

Journal Article IEEE Transactions on Communications · February 1, 2019 We propose a spatial multiplexing system using reconfigurable cavity-backed metasurface antennas. The metasurface antennas consist of a printed cavity with dynamically tunable metamaterial radiators patterned on one side and fed by multiple radio frequency ... Full text Cite

Cost-effective Integration System of Solar Cell Powered Remote Small-Size Wireless Communication

Conference 2nd International Conference on Electrical, Communication, Computer, Power and Control Engineering, ICECCPCE 2019 · February 1, 2019 in this paper, a cost-effective design technique of a combined photovoltaic solar system, with electrical energy storage (ESS) for remote areas wireless long-term communication integration system is presented and discussed. Solar systems are the only possi ... Full text Cite

Phaseless coherent and incoherent microwave ghost imaging with dynamic metasurface apertures

Journal Article Optica · December 20, 2018 Phase information and spatially coherent illumination have usually been considered indispensable components of most microwave imaging systems. Dynamic metasurface apertures (DMAs)—with their ability to generate spatially incoherent illumination—have recent ... Full text Cite

Motion compensation of the transmitter and receiver in bistatic frequency-modulated continuous-wave synthetic aperture radar

Journal Article IET Radar, Sonar and Navigation · November 1, 2018 Synthetic aperture radar (SAR) imaging with an independently moving transmitter and receiver introduces motion artefacts difficult to compensate for, especially between satellites in separate orbits that rendezvous over a target. A solution for polarisatio ... Full text Cite

Extracting the turbulent flow-field from beam emission spectroscopy images using velocimetry.

Journal Article The Review of scientific instruments · October 2018 The 2D turbulent E × B flow-field is inferred from density fluctuation images obtained with the beam emission spectroscopy diagnostic on DIII-D using the orthogonal dynamic programming velocimetry algorithm. A synthetic turbulence model is us ... Full text Cite

Precise Localization of Multiple Noncooperative Objects in a Disordered Cavity by Wave Front Shaping.

Journal Article Physical review letters · August 2018 Complicated multipath trajectories of waves in disordered cavities cause object localization to be very challenging with traditional ray-tracing approaches. Yet it is known that information about the object position is encoded in the Green's function. Afte ... Full text Cite

Single-frequency 3D synthetic aperture imaging with dynamic metasurface antennas.

Journal Article Applied optics · May 2018 Through aperture synthesis, an electrically small antenna can be used to form a high-resolution imaging system capable of reconstructing three-dimensional (3D) scenes. However, the large spectral bandwidth typically required in synthetic aperture radar sys ... Full text Cite

Linear solutions to metamaterial volume hologram design using a variational approach.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · April 2018 Multiplex volume holograms are conventionally constructed by the repeated exposure of a photosensitive medium to a sequence of external fields, each field typically being the superposition of a reference wave that reconstructs the hologram and the other be ... Full text Cite

Dynamic Metasurface Aperture as Smart Around-the-Corner Motion Detector.

Journal Article Scientific reports · April 2018 Detecting and analysing motion is a key feature of Smart Homes and the connected sensor vision they embrace. At present, most motion sensors operate in line-of-sight Doppler shift schemes. Here, we propose an alternative approach suitable for indoor enviro ... Full text Cite

Relaxation of Alignment Errors and Phase Calibration in Computational Frequency-Diverse Imaging using Phase Retrieval

Journal Article IEEE Access · March 14, 2018 We demonstrate a computational, frequency-diverse, phaseless imaging technique at microwave frequencies that minimizes the impacts of phase calibration and alignment errors on image reconstruction. Phase calibration error is introduced by means of misalign ... Full text Cite

Homogenized description and retrieval method of nonlinear metasurfaces

Journal Article Optics Communications · March 1, 2018 A patterned, plasmonic metasurface can strongly scatter incident light, functioning as an extremely low-profile lens, filter, reflector or other optical device. When the metasurface is patterned uniformly, its linear optical properties can be expressed usi ... Full text Cite

Inverse scattering with a non self-adjoint variational formulation.

Journal Article Optics express · March 2018 The weak scattering approximation is used when designing optical media that couple fields together, but to account for the interactions of multiple fields in a volume or to achieve the best efficiency, the solution must be consistent with Maxwell's equatio ... Full text Cite

Phaseless computational ghost imaging at microwave frequencies using a dynamic metasurface aperture.

Journal Article Applied optics · March 2018 We demonstrate a dynamic metasurface aperture as a unique tool for computational ghost imaging at microwave frequencies. The aperture consists of a microstrip waveguide loaded with an array of metamaterial elements, each of which couples energy from the wa ... Full text Cite

Dynamically reconfigurable holographic metasurface aperture for a Mills-Cross monochromatic microwave camera.

Journal Article Optics express · March 2018 We present a reconfigurable, dynamic beam steering holographic metasurface aperture to synthesize a microwave camera at K-band frequencies. The aperture consists of a 1D printed microstrip transmission line with the front surface patterned into an array of ... Full text Cite

Focusing Microwaves in the Fresnel Zone with a Cavity-Backed Holographic Metasurface

Journal Article IEEE Access · February 2, 2018 We present the design and experimental demonstration of a cavity-backed, holographic metasurface capable of focusing microwaves in the Fresnel zone. The circular cavity consists of two stacked plates: microwaves are injected into the bottom plate via a coa ... Full text Cite

Clarification of surface modes of a periodic nanopatch metasurface.

Journal Article Optics express · February 2018 We study the angle-dependent optical reflectance spectrum of a metasurface consisting of a periodic array of film-coupled plasmonic nanopatch particles. The nanopatch metasurface exhibits a strong, angle-independent absorption resonance at a wavelength def ... Full text Cite

A K-Band Backscatter Fiducial for Continuous Calibration in Coherent Millimeter-Wave Imaging

Journal Article IEEE Transactions on Microwave Theory and Techniques · January 1, 2018 We present a modulated ultrawideband backscatter calibration target (fiducial) intended for group delay calibration in large-aperture multitransceiver millimeter-wave imagers. The fiducial is designed to resemble a modulated point scatterer across the K-ba ... Full text Cite

Mode diversity of weakly modulated cavity antennas.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · January 2018 The radiating mode of a cavity antenna at a particular frequency is fixed. However, by actively modulating the permittivity inside the cavity, the radiating mode may be changed. Using time-independent perturbation theory, we derive the modes of a cavity pe ... Full text Cite

Multispectral metasurface hologram at millimeter wavelengths.

Journal Article Applied optics · January 2018 We demonstrate a computer-generated metasurface hologram in which four distinct images are encoded at four different W-band (75-110 GHz) frequencies. The metasurface hologram consists of a planar array of resonant metamaterial elements excited by a collima ... Full text Cite

Ku-band suspended meshed patch antenna integrated with solar cells for remote area applications

Journal Article Progress In Electromagnetics Research C · January 1, 2018 A new structure design of a dual-band suspended microstrip meshed patch antenna integrated with a polycrystalline silicon solar cell for Ku-band satellite applications is proposed and presented. This antenna element is a basic building block for a Ku-band ... Full text Cite

A reconfigurable millimeter-wave spotlight metasurface aperture integrated with a frequency-diverse microwave imager for security screening

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2018 In this paper, a spotlight imaging system integrated with a frequency-diverse aperture is presented for security-screening applications. The spotlight imager consists of holographic metasurface antennas that can dynamically be tuned to radiate spotlight pa ... Full text Cite

Synthetic aperture radar imaging with reconfigurable 1d dynamic metasurface apertures

Conference Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR · January 1, 2018 Driven by the growing need for lightweight and low-cost antennas, we investigate metasurface antennas as a potential SAR hardware platform. Metasurface antennas can generate arbitrary radiation patterns and electronically modulate them without requiring co ... Cite

Spatial intensity averaging for ghost imaging with a single-port dynamic metasurface aperture

Conference Optics InfoBase Conference Papers · January 1, 2018 We present a method for achieving spatial intensity integration of temporally coherent microwave radiation. The approach consists of averaging the instantaneous intensity over an ensemble of random radiation patterns using a single-port metasurface apertur ... Full text Cite

Reflective microwave ghost imaging with dynamic metasurface apertures

Conference Optics InfoBase Conference Papers · January 1, 2018 We demonstrate phaseless, single-frequency ghost imaging at microwave frequencies using a dynamic metasurface aperture. This aperture comprises a simplified hardware architecture for generating diverse speckle patterns by tuning an array of resonant metama ... Full text Cite

Hybrid graphene metasurfaces for high-speed mid-infrared light modulation and single-pixel imaging.

Journal Article Light, science & applications · January 2018 During the past decades, major advances have been made in both the generation and detection of infrared light; however, its efficient wavefront manipulation and information processing still encounter great challenges. Efficient and fast optoelectronic modu ... Full text Cite

W-band sparse imaging system using frequency diverse cavity-fed metasurface antennas

Journal Article IEEE Access · January 1, 2018 We experimentally demonstrate a frequency-diverse, computational imaging system at W-band frequencies utilizing an array of cavity-fed metasurface antennas. Each metasurface antenna consists of a cavity milled from aluminum stock, with an upper plate patte ... Full text Cite

Phase Retrieval in Frequency-Diverse Imaging

Conference 2018 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting, APSURSI 2018 - Proceedings · January 1, 2018 We demonstrate a phaseless computational frequency-diverse imaging system at K-band frequencies. The integration of the phase retrieval concept with computational frequency-diverse imaging is achieved by leveraging a gradient-descent based Wirtinger Flow a ... Full text Cite

Dipolar Model for Metamaterial Imaging Systems

Conference 2018 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting, APSURSI 2018 - Proceedings · January 1, 2018 We present a comprehensive simulation platform for computational microwave imaging systems based on frequency-diverse metasurface antennas (FDMAs). FDMAs consist of a waveguide patterned with complementary metamaterial elements with resonant frequencies se ... Full text Cite

Design of a Reconfigurable Metasurface Antenna for Dynamic Near-Field Focusing

Conference 2018 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting, APSURSI 2018 - Proceedings · January 1, 2018 We show the design of a dynamically reconfigurable holographic metasurface antenna for near-field beam-focusing applications. A metasurface layer is used to modulate the guided-mode reference to an aperture field of interest producing the desired radiated ... Full text Cite

Computational Millimeter-wave Spotlight Imaging using Holographic Metasurface Antennas

Conference 2018 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting, APSURSI 2018 - Proceedings · January 1, 2018 In this paper, a spotlight imaging system integrated with a frequency-diverse aperture is presented for security-screening applications. The spotlight imager consists of holographic metasurface antennas that can dynamically be tuned to radiate spotlight pa ... Full text Cite

Additive Manufacturing of a Conductive Polymer Cavity-Backed Metasurface Antenna for Computational Microwave Imaging

Conference 2018 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting, APSURSI 2018 - Proceedings · January 1, 2018 We demonstrate a new 3D printing technique, making use of a copper-polyester conductive composite filament (Electrifi) to achieve additive manufacturing of a frequency-diverse metasurface antenna. Using the 3D printed antenna, we synthesize a computational ... Full text Cite

Sparse blind deconvolution for imaging through layered media

Journal Article Optica · December 20, 2017 When imaging through layered media such as walls, the contents and thickness of the wall layers are generally not known a priori. Furthermore, compensating for their effects can be computationally intensive, as this generally requires modelling the transmi ... Full text Cite

Polarizability extraction of complementary metamaterial elements in waveguides for aperture modeling

Journal Article Physical Review B · December 4, 2017 We consider the design and modeling of metasurfaces that couple energy from guided waves to propagating wave fronts. To this purpose, we develop a comprehensive, multiscale dipolar interpretation for large arrays of complementary metamaterial elements embe ... Full text Cite

Experimental Synthetic Aperture Radar with Dynamic Metasurfaces

Journal Article IEEE Transactions on Antennas and Propagation · December 1, 2017 We investigate the use of a dynamic metasurface as the transmitting antenna for a synthetic aperture radar (SAR) imaging system. The dynamic metasurface consists of a 1-D microstrip waveguide with complementary electric resonator (cELC) elements patterned ... Full text Cite

Generalized range migration algorithm for synthetic aperture radar image reconstruction of metasurface antenna measurements

Journal Article Journal of the Optical Society of America B: Optical Physics · December 1, 2017 Waveguide-fed dynamic metasurface antennas (DMAs) can be used in a variety of synthetic aperture radar (SAR) modalities for microwave and millimeter-wave imaging. The DMA consists of an electrically large array of resonant, dynamically reconfigurable metam ... Full text Cite

Analysis of a Waveguide-Fed Metasurface Antenna

Journal Article Physical Review Applied · November 29, 2017 The metasurface concept has emerged as an advantageous reconfigurable antenna architecture for beam forming and wave-front shaping, with applications that include satellite and terrestrial communications, radar, imaging, and wireless power transfer. The me ... Full text Cite

Extracting polarizability of complementary metamaterial elements using equivalence principles

Conference 2017 11th International Congress on Engineered Material Platforms for Novel Wave Phenomena, Metamaterials 2017 · November 14, 2017 A novel Metamaterial Dipole Model (MDM) has been proposed as a powerful tool for modeling and designing metasurface antennas for numerous applications such as beamforming arrays, holograms, and flat lenses among others. In this technique, a metasurface ant ... Full text Cite

Near-field multistatic radar reconstruction with stretched-phase Fourier accelerated multistatic imaging

Journal Article IET Radar, Sonar and Navigation · November 1, 2017 There exist few rapid reconstruction methods for applications that use multistatic radar for targets in the near field such as vehicle navigation and personnel screening. Fourier accelerated multistatic imaging (FAMI) is a method that combines the rapid re ... Full text Cite

Multispectral metasurface absorbers for optoelectronic devices

Conference 2017 Conference on Lasers and Electro-Optics, CLEO 2017 - Proceedings · October 25, 2017 We demonstrate multispectral metasurfaces over wafer-scale areas exhibiting greater than 85 percent absorption, ~100 nm linewidths from 580-1125 nm by patterning plasmonic resonators in micron-scale pixels using a fusion of bottom-up and top-down fabricati ... Full text Cite

Synthesizing a frequency-diverse aperture for security-screening applications

Conference 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings · October 18, 2017 We demonstrate the design of a frequency-diverse aperture for imaging of human size objects. Frequency-diversity is an all-electronic technique, allowing the imaging to be performed without any mechanical moving parts or active circuit components. Leveragi ... Full text Cite

Alignment Correction for antenna scans in imaging

Conference 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings · October 18, 2017 In this paper, we propose a software correction technique to eliminate the misalignment errors in the measurement of antenna radiated fields for frequency-diverse imaging. It is shown that by using RF fiducials integrated into the antennas, the effect of r ... Full text Cite

Computational polarimetric localization with a radiating metasurface

Conference 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings · October 18, 2017 A novel computational technique is presented in this article for enabling the estimation of both the localization of radiating sources and their polarization states. To this end, a radiating metasurface is conceived to multiplex the polarization informatio ... Full text Cite

Optimised lambda architecture for monitoring wlcg using spark and spark streaming

Conference 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 · October 16, 2017 Full text Cite

Millimetre wave front end receivers for the MWS and MWI instruments onboard MetOp-SG satellites

Conference International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz · October 12, 2017 RAL Space and its project partner PRG are tasked with providing space-qualified heterodyne receiver front-ends operating between 165.5 GHz and 325 GHz for the Microwave Sounder (MWS), the Microwave Imager (MWI) and the Ice Cloud Imager (ICI) of the MetOp S ... Full text Cite

Discrete dipole approximation for simulation of unusually tapered leaky wave antennas

Conference IEEE MTT-S International Microwave Symposium Digest · October 4, 2017 In this paper, Discrete Dipole Approximation (DDA) is presented as a simulation tool for predicting the electromagnetic properties of one dimensional metasurface antennas and slotted waveguide antennas. The proposed method is verified by demonstrating exce ... Full text Cite

Computational polarimetric microwave imaging.

Journal Article Optics express · October 2017 We propose a polarimetric microwave imaging technique that exploits recent advances in computational imaging. We utilize a frequency-diverse cavity-backed metasurface, allowing us to demonstrate high-resolution polarimetric imaging using a single transceiv ... Full text Cite

Frequency-Diverse Computational Microwave Phaseless Imaging

Journal Article IEEE Antennas and Wireless Propagation Letters · August 31, 2017 Phaseless imaging approaches provide a significant advantage for systems where maintaining coherency during the acquisition time is difficult. Here, we demonstrate a phaseless, frequency-diverse, computational imaging system that operates at K-band frequen ... Full text Cite

Dual-Polarization Printed Holographic Multibeam Metasurface Antenna

Journal Article IEEE Antennas and Wireless Propagation Letters · August 24, 2017 Multibeam antennas have emerged as a promising concept for applications where selective beam coverage is required. Multibeam radiation can be achieved leveraging the concept of metasurfaces, enabling the radiated wavefronts to be tailored in an all-electro ... Full text Cite

Single-frequency microwave imaging with dynamic metasurface apertures

Journal Article Journal of the Optical Society of America B: Optical Physics · August 1, 2017 Conventional microwave imaging schemes, enabled by the ubiquity of coherent sources and detectors, have traditionally relied on frequency bandwidth to retrieve range information, while using mechanical or electronic beamsteering to obtain cross-range infor ... Full text Cite

Investigation of RF and DC plasma electron sources for material processing applications

Conference IVEC 2017 - 18th International Vacuum Electronics Conference · July 2, 2017 This work presents the design, development and experimental results obtained from an RF plasma cathode Electron Beam (EB) gun for material processing applications. EB currents of up to 38 mA at -60 kV were extracted and correlated to Optical Emission Spect ... Full text Cite

Scalable variable-index elasto-optic metamaterials for macroscopic optical components and devices.

Journal Article Nature communications · July 2017 Optical metamaterials with an artificial subwavelength structure offer new approaches to implement advanced optical devices. However, some of the biggest challenges associated with the development of metamaterials in the visible spectrum are the high costs ... Full text Cite

Enhanced resolution stripmap mode using dynamic metasurface antennas

Journal Article IEEE Transactions on Geoscience and Remote Sensing · July 1, 2017 To maintain sufficient signal-To-noise ratio (SNR) for image reconstruction and image interpretation, conventional synthetic aperture radar (SAR) systems must trade off resolution and scene size. This paper proposes a new SAR mode of operation, which impro ... Full text Cite

Millimeter-wave spotlight imager using dynamic holographic metasurface antennas.

Journal Article Optics express · July 2017 Computational imaging systems leverage generalized measurements to produce high-fidelity images, enabling novel and often lower cost hardware platforms at the expense of increased processing. However, obtaining full resolution images across a large field-o ... Full text Cite

Overview of NSTX Upgrade initial results and modelling highlights

Journal Article Nuclear Fusion · June 20, 2017 The National Spherical Torus Experiment (NSTX) has undergone a major upgrade, and the NSTX Upgrade (NSTX-U) Project was completed in the summer of 2015. NSTX-U first plasma was subsequently achieved, diagnostic and control systems have been commissioned, t ... Full text Cite

Computational imaging using frequency-diverse metasurfaces

Conference 2017 11th European Conference on Antennas and Propagation, EUCAP 2017 · May 15, 2017 This paper summarizes the recent advances in using frequency-diverse metasurfaces for computational imaging in the microwave and millimeter wave regimes. Frequency-diverse apertures are defined as structures that can generate distinct radiation patterns as ... Full text Cite

Computational frequency-diverse microwave imaging using an air-filled cavity-backed antenna

Conference 2017 11th European Conference on Antennas and Propagation, EUCAP 2017 · May 15, 2017 We demonstrate a frequency-diverse imaging system using an air-filled cavity-backed antenna as a transceiver (cavity-to-cavity system layout) for the K-band (17.5-26.5 GHz) frequency regime. Leveraging the computational imaging concept, the frequency-diver ... Full text Cite

Optimization of frequency-diverse antennas for computational imaging at microwave frequencies

Conference 2017 11th European Conference on Antennas and Propagation, EUCAP 2017 · May 15, 2017 Frequency-diverse imaging is an all-electronic method, capable of sampling the scene to be imaged without the need for a mechanical scan or active circuit components. In order to optimize the imaging characteristics, such as imaging resolution and fidelity ... Full text Cite

Single-frequency near-field MIMO imaging

Conference 2017 11th European Conference on Antennas and Propagation, EUCAP 2017 · May 15, 2017 A near-field radar imaging technique is presented based on single-frequency measurements from a multiple-input multiple-output (MIMO) array. Such arrays are able to fully sample the κ-space of a region of interest. Advantageously, both range and cross-rang ... Full text Cite

Synthetic aperture radar with dynamic metasurface antennas: a conceptual development.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · May 2017 We investigate the application of dynamic metasurface antennas (DMAs) to synthetic aperture radar (SAR) systems. Metasurface antennas can generate a multitude of tailored electromagnetic waveforms from a physical platform that is low-cost, lightweight, and ... Full text Cite

Efficient finite element resolution of gyromagnetic and gyroelectric nonreciprocal electromagnetic problems.

Journal Article Optics express · May 2017 We present a rigorous derivation of the weak-form formulation of the Helmholtz equation for electromagnetic structures incorporating general nonreciprocal, dispersive materials such as magnetized ferrites or magnetized free-carrier plasmas. This formulatio ... Full text Cite

Cavity-backed metasurface antennas and their application to frequency diversity imaging.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · April 2017 Frequency diversity antennas with spatially structured radiation patterns reduce the reliance on actively switched elements for beamforming which become increasingly expensive and impractical as frequency increases. As the quality factor Q of a frequency d ... Full text Cite

Effective-medium description of a metasurface composed of a periodic array of nanoantennas coupled to a metallic film

Journal Article Physical Review A · March 20, 2017 We compute the reflectance properties of a metasurface that consists of a doubly periodic array of patch nanoantennas strongly coupled to a metallic film. Each plasmonic patch antenna can be accurately modeled as a polarizable, radiating, magnetic dipole. ... Full text Cite

Recent progress in understanding electron thermal transport in NSTX

Journal Article Nuclear Fusion · March 10, 2017 The anomalous level of electron thermal transport inferred in magnetically confined configurations is one of the most challenging problems for the ultimate realization of fusion power using toroidal devices: tokamaks, spherical tori and stellarators. It is ... Full text Cite

Optimisation of millimetre wave amplifiers for satellite based radiometer

Conference Proceedings of IEEE 9th UK-Europe-China Workshop on Millimetre Waves and Terahertz Technologies, UCMMT 2016 · March 7, 2017 STFC / RAL Space has been involved in the development of an extensive variety of satellite mission payloads operating across a wide range of the electromagnetic spectrum. The RAL Space Millimetre-wave Technology Group (MMTG) has undertaken the development ... Full text Cite

Development of high temperature, radiation hard detectors based on diamond

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · February 11, 2017 Single crystal CVD diamond has many desirable properties compared to current, well developed, detector materials; exceptional radiation, chemical and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry), wide bandgap and ... Full text Cite

Toward Multispectral Imaging with Colloidal Metasurface Pixels.

Journal Article Advanced materials (Deerfield Beach, Fla.) · February 2017 Multispectral colloidal metasurfaces are fabricated that exhibit greater than 85% absorption and ≈100 nm linewidths by patterning film-coupled nanocubes in pixels using a fusion of bottom-up and top-down fabrication techniques over wafer-scale areas. With ... Full text Cite

Large Metasurface Aperture for Millimeter Wave Computational Imaging at the Human-Scale.

Journal Article Scientific reports · February 2017 We demonstrate a low-profile holographic imaging system at millimeter wavelengths based on an aperture composed of frequency-diverse metasurfaces. Utilizing measurements of spatially-diverse field patterns, diffraction-limited images of human-sized subject ... Full text Cite

X-band SAR imaging with a liquid-crystal-based dynamic metasurface antenna

Journal Article Journal of the Optical Society of America B: Optical Physics · February 1, 2017 Synthetic aperture radar (SAR) synthesizes a large effective aperture via coherent processing of multiple measurements taken from a moving platform. We present an approach for SAR imaging using an X-band (10-13.7 GHz) dynamic metasurface antenna (MSA). Thi ... Full text Cite

Diamond based detectors for high temperature, high radiation environments

Journal Article Journal of Instrumentation · January 23, 2017 Single crystal CVD diamond has many desirable properties as a radiation detector; exceptional radiation hardness and physical hardness, chemical inertness, low Z (close to human tissue, good for dosimetry and transmission mode applications), wide bandgap ( ... Full text Cite

An analysis of beamed wireless power transfer in the Fresnel zone using a dynamic, metasurface aperture

Journal Article Journal of Applied Physics · January 7, 2017 Wireless power transfer (WPT) has been an active topic of research, with a number of WPT schemes implemented in the near-field (coupling) and far-field (radiation) regimes. Here, we consider a beamed WPT scheme based on a dynamically reconfigurable source ... Full text Cite

Development of transparent patch antenna element integrated with solar cells for Ku-band satellite applications

Conference 2016 Loughborough Antennas and Propagation Conference, LAPC 2016 · January 5, 2017 In this paper, a design of broadband compact microstrip meshed patch antenna integrated with solar cells for Ku-band satellite applications is presented. A Plexiglas transparent substrate is also employed to enable the light to pass through with high effic ... Full text Cite

Fourier Accelerated Multistatic Imaging: A Fast Reconstruction Algorithm for Multiple-Input-Multiple-Output Radar Imaging

Journal Article IEEE Access · January 1, 2017 Multiple-input-multiple-output (MIMO) radar image processing presents problems difficult to address by modifying conventional monostatic radar methods as Fourier range migration. When the distance between the transmitter and receiver is comparable to the t ... Full text Cite

Versatile Manufacturing of Split-Block Microwave Devices Using Rapid Prototyping and Electroplating

Journal Article IEEE Antennas and Wireless Propagation Letters · January 1, 2017 We present a novel method of rapid prototyping waveguide and antenna using plating on plastic technique. The part is created by high-precision three-dimensional printing and plated with copper using both electroless plating and electroplating. The performa ... Full text Cite

Multispectral metasurface absorbers for optoelectronic devices

Conference Optics InfoBase Conference Papers · January 1, 2017 We demonstrate multispectral metasurfaces over wafer-scale areas exhibiting greater than 85 percent absorption, ~100 nm linewidths from 580-1125 nm by patterning plasmonic resonators in micron-scale pixels using a fusion of bottom-up and top-down fabricati ... Full text Cite

Near field scan alignment procedure for electrically large apertures

Journal Article IEEE Transactions on Antennas and Propagation · January 1, 2017 Computational imaging at microwave frequencies has gained traction due to its potential for obtaining high-quality images with fast acquisition rates. Complex and diverse radiation patterns form the cornerstone of this approach. Electrically large antennas ... Full text Cite

Design and Analysis of a W-Band Metasurface-Based Computational Imaging System

Journal Article IEEE Access · January 1, 2017 We design and numerically analyze a coherent computational imaging system that utilizes a sparse detector array of planar, frequency-diverse, metasurface antennas designed to operate over the W-band frequency range (75-110 GHz). Each of the metasurface ant ... Full text Cite

Security screening via computational imaging using frequency-diverse metasurface apertures

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2017 Computational imaging is a proven strategy for obtaining high-quality images with fast acquisition rates and simpler hardware. Metasurfaces provide exquisite control over electromagnetic fields, enabling the radiated field to be molded into unique patterns ... Full text Cite

Alternative synthetic aperture radar (SAR) modalities using a 1D dynamic metasurface antenna

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2017 Synthetic aperture radar (SAR) systems conventionally rely on mechanically-Actuated reflector dishes or large phased arrays for generating steerable directive beams. While these systems have yielded high-resolution images, the hardware suffers from conside ... Full text Cite

Reconfigurable metasurface aperture for security screening and microwave imaging

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2017 Microwave imaging systems have seen growing interest in recent decades for applications ranging from security screening to space/earth observation. However, hardware architectures commonly used for this purpose have not seen drastic changes. With the adven ... Full text Cite

Adapting range migration techniques for imaging with metasurface antennas: Analysis and limitations

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2017 Dynamic metasurface antennas are planar structures that exhibit remarkable capabilities in controlling electromagnetic wave-fronts, advantages which are particularly attractive for microwave imaging. These antennas exhibit strong frequency dispersion and p ... Full text Cite

Design and Analysis of a Reconfigurable Holographic Metasurface Aperture for Dynamic Focusing in the Fresnel Zone

Journal Article IEEE Access · January 1, 2017 We present numerical simulations of the near-field focusing capabilities of a dynamically reconfigurable holographic metasurface aperture. The aperture consists of a parallel-plate waveguide in which the upper plate is patterned with a number of metamateri ... Full text Cite

Feed and loss effects in spherical lens antennas for satellite communications

Journal Article International Journal of RF and Microwave Computer-Aided Engineering · January 1, 2017 The hemispherical lens antenna is a candidate for satellite communications-on-the-move, offering good scan performance in a reduced height. A short focal length minimizes height but presents challenges in illuminating the lens. Aperture efficiency is domin ... Full text Cite

Transformation-optics simulation method for stimulated Brillouin scattering

Journal Article Physical Review A · December 7, 2016 We develop an approach to enable the full-wave simulation of stimulated Brillouin scattering and related phenomena in a frequency-domain, finite-element environment. The method uses transformation-optics techniques to implement a time-harmonic coordinate t ... Full text Cite

Digital holography based submicron thermometry.

Journal Article Optics express · December 2016 Here we introduce a phase-shifting digital holography-based method to determine the temperature profile around an irradiated (sub-)micron spherical bead. The method utilizes a Mach-Zehnder interferometer implemented into an open setup microscope. The resul ... Full text Cite

An efficient strategy for the collection and storage of large volumes of data for computation

Journal Article Journal of Big Data · December 1, 2016 In recent years, there has been an increasing amount of data being produced and stored, which is known as Big Data. The social networks, internet of things, scientific experiments and commercial services play a significant role in generating a vast amount ... Full text Cite

Microwave Imaging Using a Disordered Cavity with a Dynamically Tunable Impedance Surface

Journal Article Physical Review Applied · November 29, 2016 We perform microwave imaging using a dynamically reconfigurable aperture based on a tunable disordered cavity. The electrically large cavity is cubic with a spherical deformation and supports a multitude of distinct electromagnetic modes that vary as a fun ... Full text Cite

Field repeatability in frequency diverse imaging

Conference 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings · October 25, 2016 We consider multi-static imaging systems composed of frequency-diverse transmitting antenna arrays (or apertures). In these frequency diverse imaging modalities, accurate near-field characterization of the antennas is vital to achieving imaging. It is show ... Full text Cite

Metallization of a 3D printed cavitiy for imaging

Conference 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings · October 25, 2016 In this paper, we propose a metallized 3D printed cavity for K-band imaging and investigate the effect of metallization type on mode diversity and image reconstruction. The 3D printed cavity acts as a frequency-diverse aperture and is capable of imaging ob ... Full text Cite

Discrete dipole approximation for the simulation of the edge effects on metasurfaces

Conference 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings · October 25, 2016 A dipole-based simulation method is presented to study the effects of edges on finite metasurfaces. This technique can accurately account for the physical limitations associated with fabrication and thereby leads to high fidelity predictions needed in prac ... Full text Cite

Toward a tunable mode-mixing cavity for computational imaging

Conference 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings · October 25, 2016 A mode-mixing cavity, consisting of an electrically-large rectangular cavity with one deformed corner, supports distinct modes as a function of driving frequency. Perforating one side of this cavity, the modes formed within can be projected into an imaging ... Full text Cite

Analytical modeling of printed metasurface cavities for computational imaging

Journal Article Journal of Applied Physics · October 14, 2016 We derive simple analytical expressions to model the electromagnetic response of an electrically large printed cavity. The analytical model is then used to develop printed cavities for microwave imaging purposes. The proposed cavity is excited by a cylindr ... Full text Cite

Application of range migration algorithms to imaging with a dynamic metasurface antenna

Journal Article Journal of the Optical Society of America B: Optical Physics · October 1, 2016 Dynamic metasurface antennas are planar structures that exhibit remarkable capabilities in controlling electromagnetic wavefronts, advantages that are particularly attractive for microwave imaging. These antennas exhibit strong frequency dispersion and pro ... Full text Cite

Multistatic microwave imaging with arrays of planar cavities

Journal Article IET Microwaves, Antennas and Propagation · August 20, 2016 The authors present a multistatic imaging system at microwave frequencies based on arrays of planar cavity sub-apertures, or panels. The cavity imager consists of sets of transmit and receive panels, loaded with radiating irises distributed over the sub-ap ... Full text Cite

Phase and magnitude constrained metasurface holography at W-band frequencies.

Journal Article Optics express · August 2016 Holographic optics are an essential tool for the control of light, generating highly complex and tailored light field distributions that can represent physical objects or abstract information. Conceptually, a hologram is a region of space in which an arbit ... Full text Cite

Dual purpose antenna for hybrid free space optics/RF communication systems

Journal Article Journal of Lightwave Technology · July 15, 2016 The concept of hybrid free space optical/radio frequency (FSO/RF) communications has been considered for the last mile access network applications. The existing schemes mostly use two separate transceiver antennas for outdoor terrestrial links of few kilom ... Full text Cite

Phaseless computational imaging with a radiating metasurface.

Journal Article Optics express · July 2016 Computational imaging modalities support a simplification of the active architectures required in an imaging system and these approaches have been validated across the electromagnetic spectrum. Recent implementations have utilized pseudo-orthogonal radiati ... Full text Cite

Theory of patch-antenna metamaterial perfect absorbers

Journal Article Physical Review A · June 27, 2016 A metasurface that absorbs waves from all directions of incidence can be achieved if the surface impedance is made to vary as a function of incidence angle in a specific manner. Here we show that a periodic array of planar nanoparticles coupled to a metal ... Full text Cite

Design considerations for a dynamic metamaterial aperture for computational imaging at microwave frequencies

Journal Article Journal of the Optical Society of America B: Optical Physics · June 1, 2016 We investigate the imaging capabilities of a one-dimensional, dynamic, metamaterial aperture that operates at the lower part of K-band microwave frequencies (17.5-21.1 GHz). The dynamic aperture consists of a microstrip transmission line with an array of r ... Full text Cite

Additive manufacturing of waveguide for Ku-band satellite communications antenna

Conference 2016 10th European Conference on Antennas and Propagation, EuCAP 2016 · May 31, 2016 A metal waveguide feed chain in a Ku-band scanning lens array antenna comprises 5 parts. These are: two iris polarisers, two bend-feeds, and a central power combiner. The combiner comprises a pair of septum polarisers and tee junctions. The feed chain gene ... Full text Cite

Printed Aperiodic Cavity for Computational and Microwave Imaging

Journal Article IEEE Microwave and Wireless Components Letters · May 1, 2016 We demonstrate a frequency-diverse aperture for microwave imaging based on a planar cavity at K-band frequencies (18-26.5 GHz). The structure consists of an array of radiating circular irises patterned into the front surface of a double-sided printed circu ... Full text Cite

Spatially resolving antenna arrays using frequency diversity.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · May 2016 Radio imaging devices and synthetic aperture radar typically use either mechanical scanning or phased arrays to illuminate a target with spatially varying radiation patterns. Mechanical scanning is unsuitable for many high-speed imaging applications, and p ... Full text Cite

Frequency-diverse microwave imaging using planar Mills-Cross cavity apertures.

Journal Article Optics express · April 2016 We demonstrate a frequency diverse, multistatic microwave imaging system based on a set of transmit and receive, radiating, planar cavity apertures. The cavities consist of double-sided, copper-clad circuit boards, with a series of circular radiating irise ... Full text Cite

Evolution patterns and parameter regimes in edge localized modes on the National Spherical Torus Experiment

Journal Article Plasma Physics and Controlled Fusion · January 28, 2016 We implement unsupervised machine learning techniques to identify characteristic evolution patterns and associated parameter regimes in edge localized mode (ELM) events observed on the National Spherical Torus Experiment. Multi-channel, localized measureme ... Full text Cite

Influence of spatial dispersion in metals on the optical response of deeply subwavelength slit arrays

Journal Article Physical Review B · January 13, 2016 In the framework of the hydrodynamic model describing the response of electrons in a metal, we show that arrays of very narrow and shallow metallic slits have an optical response that is influenced by the spatial dispersion in metals arising from the repul ... Full text Cite

Waveguide-Fed Tunable Metamaterial Element for Dynamic Apertures

Journal Article IEEE Antennas and Wireless Propagation Letters · January 1, 2016 We present the design of a tunable metamaterial element that can serve as the building block for a dynamically reconfigurable aperture. The element - a complimentary electric-LC (cELC) resonator - is patterned into the upper conductor of a microstrip trans ... Full text Cite

Special issue on transformation optics

Journal Article Journal of Optics (United Kingdom) · January 1, 2016 Full text Cite

Software Calibration of a Frequency-Diverse, Multistatic, Computational Imaging System

Journal Article IEEE Access · January 1, 2016 We demonstrate a technique for calibrating a frequency-diverse, multistatic, computational imaging system. A frequency-diverse aperture enables an image to be reconstructed primarily from a set of scattered field measurements taken over a band of frequenci ... Full text Cite

Design and Simulation of a Frequency-Diverse Aperture for Imaging of Human-Scale Targets

Journal Article IEEE Access · January 1, 2016 We present the design and simulation of a frequency-diverse aperture for imaging of human-size targets at microwave wavelengths. Predominantly relying on a frequency sweep to produce diverse radiation patterns, the frequency-diverse aperture provides a pat ... Full text Cite

Discrete Dipole Approximation Applied to Highly Directive Slotted Waveguide Antennas

Journal Article IEEE Antennas and Wireless Propagation Letters · January 1, 2016 We present an analysis of a slotted waveguide antenna (SWA) whose directivity has been enhanced by using metamaterial parasitic elements. We apply an adapted form of the discrete dipole approximation (DDA) as a modeling tool and verify the accuracy and ver ... Full text Cite

Investigation of alignment errors on multi-static microwave imaging based on frequency-diverse metamaterial apertures

Journal Article Progress In Electromagnetics Research B · January 1, 2016 We examine the effect of alignment errors on the performance of a frequency-diverse imaging system composed of metamaterial apertures. In a frequency-diverse imaging system, a sequence of distinct radiation patterns, indexed by frequency, provides measurem ... Full text Cite

Wireless Power Transfer in the Radiative Near Field

Journal Article IEEE Antennas and Wireless Propagation Letters · January 1, 2016 A scheme for wireless power transfer (WPT) in the radiative near-field (Fresnel) region is presented. The proposed Fresnel WPT scheme is designed to focus microwaves to a diffraction-limited region where a detector can be positioned, achieving reasonably h ... Full text Cite

Electro-optic and radiation damage performance of the CIS115, an imaging sensor for the JANUS optical camera onboard JUICE

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2016 The Jupiter Icy Moon Explorer (JUICE) has been officially adopted as the next Large class mission by the European Space Agency, with a launch date of 2022. The science payload includes an optical camera, JANUS, which will perform imaging and mapping observ ... Full text Cite

Unification of compressed imaging techniques in the microwave range and deconvolution strategy

Conference 2015 European Radar Conference, EuRAD 2015 - Proceedings · December 2, 2015 In recent years, several techniques of imaging have emerged based on compressive sensing. Thus, using passive devices able to code and sum the information measured on a radiating aperture, complex UWB beamforming hardwares can be replaced by inverse proble ... Full text Cite

Large-Area Metasurface Perfect Absorbers from Visible to Near-Infrared.

Journal Article Advanced materials (Deerfield Beach, Fla.) · December 2015 An absorptive metasurface based on film-coupled colloidal silver nanocubes is demonstrated. The metasurfaces are fabricated using simple dip-coating methods and can be deposited over large areas and on arbitrarily shaped objects. The surfaces show nearly c ... Full text Cite

Optical bistability with film-coupled metasurfaces.

Journal Article Optics letters · December 2015 Metasurfaces comprising arrays of film-coupled, nanopatch antennas are a promising platform for low-energy, all-optical switches. The large field enhancements that can be achieved in the dielectric spacer region between the nanopatch and the metallic subst ... Full text Cite

Wake control with permeable multilayer structures: The spherical symmetry case.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · December 2015 We explore the possibility of controlling the wake and drag of a spherical object independently of each other, using radial distributions of permeability in the Brinkman-Stokes formalism. By discretizing a graded-permeability shell into discrete, macroscop ... Full text Cite

Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment

Journal Article Physics of Plasmas · December 1, 2015 Theory and experiments have shown that electron temperature gradient (ETG) turbulence on the electron gyro-scale, k⊥ρe ≲ 1, can be responsible for anomalous electron thermal transport in NSTX. Electron scale (high-k) turbulence is diagnosed in NSTX with a ... Full text Cite

Dynamic metamaterial aperture for microwave imaging

Journal Article Applied Physics Letters · November 16, 2015 We present a dynamic metamaterial aperture for use in computational imaging schemes at microwave frequencies. The aperture consists of an array of complementary, resonant metamaterial elements patterned into the upper conductor of a microstrip line. Each m ... Full text Cite

Comprehensive simulation platform for a metamaterial imaging system.

Journal Article Applied optics · November 2015 Recently, a frequency-diverse, metamaterial-based aperture has been introduced in the context of microwave and millimeter wave imaging. The generic form of the aperture is that of a parallel plate waveguide, in which complementary metamaterial elements pat ... Full text Cite

Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

Journal Article Physics of Plasmas · November 1, 2015 In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heate ... Full text Cite

Directional plasmonic nanoantennas to enhance the purcell effect

Conference 2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), USNC-URSI 2015 - Proceedings · October 21, 2015 We will present plasmonic nanoantennas, composed of silver nanocubes strongly coupled to gold films, which are the optical and infrared (IR) frequency counterparts to the well-established patch antennas used in microwave frequencies for mobile communicatio ... Full text Cite

Probe configuration study for the metamaterial aperture imager

Conference 2015 9th European Conference on Antennas and Propagation, EuCAP 2015 · August 27, 2015 We investigate a metamaterial imager (metaimager) consisting of one transmitting metamaterial panel and a collection of broadband receiving probes. Image reconstruction is performed by interrogating a scene with a set of radiative measurement modes encoded ... Cite

Comparison of different reconstruction algorithms for image reconstruction in metamaterial aperture based imaging system

Conference 2015 9th European Conference on Antennas and Propagation, EuCAP 2015 · August 27, 2015 We investigate the performance of various image reconstruction algorithms for the design of a metamaterial aperture-based imaging system. The metamaterial imaging system consists of a transmitting metamaterial aperture panel and a receiving low-gain probe ... Cite

Plasmonic nanopatch antennas for large purcell enhancement

Conference Conference on Lasers and Electro-Optics Europe - Technical Digest · August 10, 2015 We demonstrate Purcell enhancements of-1000 from fluorescent molecules embedded in a plasmonic antenna with sub-10 nm gap between metals. Simulations and experiments reveal the high radiative efficiency and directionality of the antenna. ... Cite

Large and ultrafast nonlinear absorption of an air/gold plasmonic waveguide

Conference Conference on Lasers and Electro-Optics Europe - Technical Digest · August 10, 2015 We investigate theoretically and experimentally the nonlinear propagation of surface plasmons on an air/gold interface which reveals large and ultrafast (∼100 fs) self-induced absorption. The experiment enables a direct measurement of the third-order nonli ... Cite

Scaling of the nonlinear response of metal/dielectric plasmonic waveguides

Conference Conference on Lasers and Electro-Optics Europe - Technical Digest · August 10, 2015 The scaling of the nonlinear response of a single-interface plasmonic waveguide is studied, where both the metal and dielectric display nonlinearity. We introduce a figure-of-merit that guides metal/dielectric nanophotonic device design for specific applic ... Cite

Analytic modeling of metmaterial absorbers

Conference Conference on Lasers and Electro-Optics Europe - Technical Digest · August 10, 2015 We present a fully analytical model that describes ideal absorbing metasurfaces composed of film-coupled optical nanoantennas. The model predicts the spectrum and the angular dependence of the absorption and is compared to full-wave numerical simulations. ... Cite

Studying the interplay of electric and magnetic resonance-enhanced second harmonic generation: Theory and experiments

Conference Conference on Lasers and Electro-Optics Europe - Technical Digest · August 10, 2015 We present an experimental study of a metasurface, which exhibits electric and magnetic resonances, in order to understand their independent contributions to second-harmonic generation. A hydrodynamic model framework is used to match experimental results. ... Cite

Quasi-Static Magnetic Field Shielding Using Longitudinal Mu-Near-Zero Metamaterials.

Journal Article Scientific reports · August 2015 The control of quasi-static magnetic fields is of considerable interest in applications including the reduction of electromagnetic interference (EMI), wireless power transfer (WPT), and magnetic resonance imaging (MRI). The shielding of static or quasi-sta ... Full text Cite

Numerical tool to take nonlocal effects into account in metallo-dielectric multilayers.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · August 2015 We provide a numerical tool to quantitatively study the impact of nonlocality arising from free electrons in metals on the optical properties of metallo-dielectric multilayers. We found that scattering matrices are particularly well suited to take into acc ... Full text Cite

Ultrafast spontaneous emission source using plasmonic nanoantennas.

Journal Article Nature communications · July 2015 Typical emitters such as molecules, quantum dots and semiconductor quantum wells have slow spontaneous emission with lifetimes of 1-10 ns, creating a mismatch with high-speed nanoscale optoelectronic devices such as light-emitting diodes, single-photon sou ... Full text Cite

Clarifying the origin of third-harmonic generation from film-coupled nanostripes.

Journal Article Optics express · July 2015 The resonance associated with plasmonic nanostructures strongly enhances local optical fields, and can thus dramatically enhance the nonlinear response of the composite structure. However, the origin of the nonlinear signal generated from hybrid nanostruct ... Full text Cite

Reduced height Luneburg lens antennas for satellite communications-on-the-move

Conference Proceedings of 14th Conference on Microwave Techniques, COMITE 2015 · June 9, 2015 The hemispherical (or half-Luneburg) lens antenna is a candidate type for satellite communications-on-the-move, either singly or as an element in a small array. It offers good aperture efficiency in a reduced height and excellent scanning performance. This ... Full text Cite

Ultrafast self-action of surface-plasmon polaritons at an air/metal interface

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 11, 2015 We investigate both theoretically and experimentally the nonlinear propagation of surface-plasmon polaritons (SPP) on a single air/metal interface. Inspired by nonlinear dielectric waveguide theory, we analytically derive a model that describes the nonline ... Full text Cite

Computational imaging using a mode-mixing cavity at microwave frequencies

Journal Article Applied Physics Letters · May 11, 2015 We present a 3D computational imaging system based on a mode-mixing cavity at microwave frequencies. The core component of this system is an electrically large rectangular cavity with one corner re-shaped to catalyze mode mixing, often called a Sinai Billi ... Full text Cite

Third-harmonic generation in the presence of classical nonlocal effects in gap-plasmon nanostructures

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 8, 2015 Classical nonlocality in conducting nanostructures has been shown to dramatically alter the linear optical response by placing a fundamental limit on the maximum field enhancement that can be achieved. This limit directly extends to all nonlinear processes ... Full text Cite

Scaling of the nonlinear response of metal/dielectric plasmonic waveguides

Conference CLEO: QELS - Fundamental Science, CLEO_QELS 2015 · May 4, 2015 The scaling of the nonlinear response of a single-interface plasmonic waveguide is studied, where both the metal and dielectric display nonlinearity. We introduce a figure-of-merit that guides metal/dielectric nanophotonic device design for specific applic ... Full text Cite

Plasmonic nanopatch antennas for large purcell enhancement

Conference CLEO: QELS - Fundamental Science, CLEO_QELS 2015 · May 4, 2015 We demonstrate Purcell enhancements of ~1000 from fluorescent molecules embedded in a plasmonic antenna with sub-10 nm gap between metals. Simulations and experiments reveal the high radiative efficiency and directionality of the antenna. © OSA 2015. ... Full text Cite

Analytic modeling of metmaterial absorbers

Conference CLEO: QELS - Fundamental Science, CLEO_QELS 2015 · May 4, 2015 We present a fully analytical model that describes ideal absorbing metasurfaces composed of film-coupled optical nanoantennas. The model predicts the spectrum and the angular dependence of the absorption and is compared to full-wave numerical simulations. ... Full text Cite

Studying the interplay of electric and magnetic resonance- enhanced second harmonic generation: Theory and experiments

Conference CLEO: QELS - Fundamental Science, CLEO_QELS 2015 · May 4, 2015 We present an experimental study of a metasurface, which exhibits electric and magnetic resonances, in order to understand their independent contributions to second-harmonic generation. A hydrodynamic model framework is used to match experimental results. ... Full text Cite

Large and ultrafast nonlinear absorption of an air/gold plasmonic waveguide

Conference CLEO: QELS - Fundamental Science, CLEO_QELS 2015 · May 4, 2015 We investigate theoretically and experimentally the nonlinear propagation of surface plasmons on an air/gold interface which reveals large and ultrafast (~100 fs) self-induced absorption. The experiment enables a direct measurement of the third-order nonli ... Full text Cite

Leveraging Nanocavity Harmonics for Control of Optical Processes in 2D Semiconductors.

Journal Article Nano letters · May 2015 Optical cavities with multiple tunable resonances have the potential to provide unique electromagnetic environments at two or more distinct wavelengths--critical for control of optical processes such as nonlinear generation, entangled photon generation, or ... Full text Cite

Correlations between quasi-coherent fluctuations and the pedestal evolution during the inter-edge localized modes phase on DIII-D

Journal Article Physics of Plasmas · May 1, 2015 Direct measurements of the pedestal recovery during an edge-localized mode cycle provide evidence that quasi-coherent fluctuations (QCFs) play a role in the inter-ELM pedestal dynamics. Using fast Thomson scattering measurements, the pedestal density and t ... Full text Cite

Comparison of beam emission spectroscopy and gas puff imaging edge fluctuation measurements in National Spherical Torus Experiment

Journal Article Physics of Plasmas · May 1, 2015 In this study, the close physical proximity of the Gas Puff Imaging (GPI) and Beam Emission Spectroscopy (BES) diagnostics on the National Spherical torus Experiment (NSTX) is leveraged to directly compare fluctuation measurements, and to study the local e ... Full text Cite

Microwave inverse scattering using scalar indirect holographic techniques

Conference Mediterranean Microwave Symposium · April 17, 2015 This paper describes the use of indirect microwave holographic together with inverse scattering techniques for the reconstruction of the dielectric properties of unknown objects. The use of indirect microwave holography enables the complex field scattered ... Full text Cite

An overview of recent physics results from NSTX

Journal Article Nuclear Fusion · March 27, 2015 The National Spherical Torus Experiment (NSTX) is currently being upgraded to operate at twice the toroidal field and plasma current (up to 1T and 2MA), with a second, more tangentially aimed neutral beam (NB) for current and rotation control, allowing for ... Full text Cite

The development of indirect microwave holography for measurement and imaging applications

Conference Mediterranean Microwave Symposium · January 7, 2015 This work describes the development of indirect holographic techniques for microwave measurements and imaging. It outlines the basic theory of indirect holography and how it relates to optical holographic techniques. It starts with a description of the ini ... Full text Cite

Nanogap-enhanced infrared spectroscopy with template-stripped wafer-scale arrays of buried plasmonic cavities.

Journal Article Nano letters · January 2015 We have combined atomic layer lithography and template stripping to produce a new class of substrates for surface-enhanced infrared absorption (SEIRA) spectroscopy. Our structure consists of a buried and U-shaped metal-insulator-metal waveguide whose folde ... Full text Cite

Resolution of the frequency diverse metamaterial aperture imager

Journal Article Progress in Electromagnetics Research · January 1, 2015 The resolution of a frequency diverse compressive metamaterial aperture imager is investigated. The aperture consists of a parallel plate waveguide, in which an array of complementary, resonant metamaterial elements is patterned into one of the plates. Mic ... Full text Cite

A constitutive description of nonlinear metamaterials through electric, magnetic, and magnetoelectric nonlinearities

Journal Article Springer Series in Materials Science · January 1, 2015 Nonlinear metamaterials provide a host of interesting phenomena which, like for their linear counterpart, can be described using homogenized, effective properties. Following the convention used in nonlinear optics, the response of nonlinear metamaterials c ... Full text Cite

Scaling of the nonlinear response of the surface plasmon polariton at a metal/dielectric interface

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 2015 Plasmonic systems involve interfaces containing metal and dielectric materials. In an effort to investigate the scaling of the nonlinear response of the surface plasmon polariton at a metal/dielectric interface, where the metal and dielectric present optic ... Full text Cite

Nonlinear Metal/Dielectric Plasmonic Interfaces

Conference Nonlinear Optics, NLO 2015 · January 1, 2015 We investigate theoretically and experimentally the optical nonlinearity of metal/dielectric interfaces, which provides a metric that predicts the scaling of self-action as well as a means to measure χ(3)of gold using surface plasmon polaritons. ... Full text Cite

Second harmonic generation with plasmonic metasurfaces: Direct comparison of electric and magnetic resonances

Journal Article Optical Materials Express · January 1, 2015 Plasmonic resonances in metallic nanostructures have been shown to drastically enhance local electromagnetic fields, and thereby increase the efficiency of nonlinear optical phenomena, such as second harmonic generation (SHG). While it has been experimenta ... Full text Cite

Metamaterial resonators for dynamic spatial millimeter-wave modulators

Conference Proceedings of Frontiers in Optics 2015, FIO 2015 · January 1, 2015 © OSA 2015. Many phase spatial modulators exist at optical frequencies such as liquid crystal cells. We present an alternative for millimeter-waves based on metamaterial resonators that produces strong phase modulation from a small tuning range. ... Cite

Monitoring WLCG with lambda-architecture: A new scalable data store and analytics platform for monitoring at petabyte scale.

Conference Journal of Physics: Conference Series · January 1, 2015 Monitoring the WLCG infrastructure requires the gathering and analysis of a high volume of heterogeneous data (e.g. data transfers, job monitoring, site tests) coming from different services and experiment-specific frameworks to provide a uniform and flexi ... Full text Cite

Stabilization of electron-scale turbulence by electron density gradient in NSTX

Conference 42nd European Physical Society Conference on Plasma Physics, EPS 2015 · January 1, 2015 Cite

Inter-ELM pedestal evolution and the role of edge fluctuations in the C-Mod and DIII-D tokamaks

Conference 42nd European Physical Society Conference on Plasma Physics, EPS 2015 · January 1, 2015 Cite

Third-Harmonic Generation Enhancement by Film-Coupled Plasmonic Stripe Resonators

Journal Article ACS Photonics · November 19, 2014 Because of their ability to strongly localize and enhance optical fields, plasmonic nanostructures have the potential to dramatically amplify the inherent nonlinear response of materials. We illustrate the impact of this plasmonic interaction by investigat ... Full text Cite

Probing the mechanisms of large Purcell enhancement in plasmonic nanoantennas

Journal Article Nature Photonics · November 5, 2014 To move nanophotonic devices such as lasers and single-photon sources into the practical realm, a challenging list of requirements must be met, including directional emission, room-temperature and broadband operation, high radiative quantum efficiency and ... Full text Cite

Coupled-mode theory for film-coupled plasmonic nanocubes

Journal Article Physical Review B - Condensed Matter and Materials Physics · November 3, 2014 Planar metallic nanoparticles separated by nanoscale distances from a metal film support unique plasmonic resonances useful for controlling a wide range of photodynamic processes. The fundamental resonance of a film-coupled planar nanoparticle arises from ... Full text Cite

Numerical studies of the modification of photodynamic processes by film-coupled plasmonic nanoparticles

Journal Article Journal of the Optical Society of America B: Optical Physics · November 1, 2014 The local plasmon resonances of metallic nanostructures are commonly associated with massive local field enhancements, capable of increasing the photoexcitation of nearby quantum emitters by orders of magnitude. However, these same plasmonic structures sup ... Full text Cite

Giant fluorescence enhancement of molecules coupled to plasmonic nanoscale patch antennas

Conference Frontiers in Optics, FiO 2014 · October 14, 2014 © OSA 2014. We demonstrate a colloidally synthesized and tunable plasmonic platform for giant fluorescence enhancement and increased spontaneous emission rate of embedded fluorophores. A transition between fluorescence enhancement and quenching is revealed ... Cite

Second harmonic generation by metamagnetics: Interplay of electric and magnetic resonances

Conference Frontiers in Optics, FiO 2014 · October 14, 2014 © OSA 2014. We present the first experimental study of the interplay of electric and magnetic resonances in a metamaterial to measure their independent contributions to second-harmonic generation. Experiments indicate evident contribution to SHG from funda ... Cite

Comparison of different combining methods for space-diversity FSO systems

Conference 2014 9th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2014 · October 14, 2014 This paper gives an overview of different signal combining schemes for free space optical (FSO) communication systems employing spatial diversity (SD) for the case of lognormal weak turbulence atmospheric channels. The receiver configurations are explained ... Full text Cite

Enhanced optical bistability with film-coupled plasmonic nanocubes

Journal Article Applied Physics Letters · October 2, 2014 Colloidally synthesized nanocubes strongly coupled to conducting films hold great promise for enhancing different nonlinear optical processes. They exhibit a robust and sensitive scattering response that can be easily controlled by their geometrical and ma ... Full text Cite

Metamaterial microwave holographic imaging system.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · October 2014 We demonstrate a microwave imaging system that combines advances in metamaterial aperture design with emerging computational imaging techniques. The flexibility inherent to guided-wave, complementary metamaterials enables the design of a planar antenna tha ... Full text Cite

Nanoparticle-Film Plasmon Ruler Interrogated with Transmission Visible Spectroscopy.

Journal Article ACS photonics · October 2014 The widespread use of plasmonic nanorulers (PNRs) in sensing platforms has been plagued by technical challenges associated with the development of methods to fabricate precisely controlled nanostructures with high yield and characterize them with high thro ... Full text Cite

Wideband coaxial to substrate-integrated waveguide transition in a multilayer reconfigurable antenna configuration

Journal Article IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · September 18, 2014 A low-profile, wideband transition between a coaxial waveguide and a substrate integrated waveguide (SIW) is presented in this paper. The transition is designed for a reconfigurable metamaterial antenna realized in multilayer Printed Circuit Board at X-ban ... Full text Cite

Effect of a deuterium gas puff on the edge plasma in NSTX

Journal Article Plasma Physics and Controlled Fusion · September 1, 2014 This paper describes a detailed examination of the effects of a relatively small pulsed deuterium gas puff on the edge plasma and edge turbulence in NSTX. This gas puff caused little or no change in the line-averaged plasma density or total stored energy, ... Full text Cite

Control of radiative processes using tunable plasmonic nanopatch antennas.

Journal Article Nano letters · August 2014 The radiative processes associated with fluorophores and other radiating systems can be profoundly modified by their interaction with nanoplasmonic structures. Extreme electromagnetic environments can be created in plasmonic nanostructures or nanocavities, ... Full text Open Access Cite

Progress in understanding the enhanced pedestal H-mode in NSTX

Journal Article Nuclear Fusion · August 1, 2014 This paper describes the enhanced pedestal (EP) H-mode observed in the National Spherical Torus Experiment (NSTX). The defining characteristics of EP H-mode are given, namely (i) transition after the L- to H-mode transition, (ii) region of very steep ion t ... Full text Cite

Voltage switching of a VO2 memory metasurface using ionic gel

Journal Article Applied Physics Letters · July 28, 2014 We demonstrate an electrolyte-based voltage tunable vanadium dioxide (VO2) memory metasurface. Large spatial scale, low voltage, non-volatile switching of terahertz (THz) metasurface resonances is achieved through voltage application using an ionic gel to ... Full text Cite

Two-dimensional metamaterial device design in the discrete dipole approximation

Journal Article Journal of Applied Physics · July 28, 2014 We extend the discrete dipole method to enable the analysis and design of two-dimensional magnetoelectric metamaterial devices based on transformation optics. Key to this method is the evaluation of the dipole moments of the metamaterial elements, which ca ... Full text Cite

Ultrafast self-action in an air/gold plasmonic waveguide

Conference Optics InfoBase Conference Papers · July 21, 2014 Cite

Analysis and modeling of metamaterial absorbers

Conference Optics InfoBase Conference Papers · July 21, 2014 Cite

Ultrafast self-action in an air/gold plasmonic waveguide

Conference Optics InfoBase Conference Papers · July 21, 2014 Cite

Analysis and modeling of metamaterial absorbers

Conference Optics InfoBase Conference Papers · July 21, 2014 Cite

Metamaterials. A cloaking coating for murky media.

Journal Article Science (New York, N.Y.) · July 2014 Full text Cite

Quasi-conformal approaches for two and three-dimensional transformation optical media

Chapter · July 1, 2014 Transformation optical design is generally complicated by the requirement for highly anisotropic and inhomogeneous constituent materials. Quasi-conformal mappings have appeared as an attractive subset of the general transformation optics method because the ... Full text Cite

One-way glass for microwaves using nonreciprocal metamaterials.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · May 2014 We introduce a class of nonreciprocal metamaterials based on composite assemblies of metallic and biased ferrimagnetic elements. We show that such structures act as ultrathin one-way glasses due to the competition between two modes at the surface of the fe ... Full text Cite

Light sterile neutrino sensitivity at the nuSTORM facility

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · April 9, 2014 A facility that can deliver beams of electron and muon neutrinos from the decay of a stored muon beam has the potential to unambiguously resolve the issue of the evidence for light sterile neutrinos that arises in short-baseline neutrino oscillation experi ... Full text Cite

A versatile smart transformation optics device with auxetic elasto-electromagnetic metamaterials.

Journal Article Scientific reports · February 2014 Synergistic integration of electromagnetic (EM) and mechanical properties of metamaterials, a concept known as smart metamaterials, promises new applications across the spectrum, from flexible waveguides to shape-conforming cloaks. These applications becam ... Full text Cite

Film-coupled nanoparticles by atomic layer deposition: Comparison with organic spacing layers

Journal Article Applied Physics Letters · January 13, 2014 Film-coupled nanoparticle systems have proven a reliable platform for exploring the field enhancement associated with sub-nanometer sized gaps between plasmonic nanostructures. In this Letter, we present a side-by-side comparison of the spectral properties ... Full text Cite

Magnetic metamaterial superlens for increased range wireless power transfer.

Journal Article Scientific reports · January 2014 The ability to wirelessly power electrical devices is becoming of greater urgency as a component of energy conservation and sustainability efforts. Due to health and safety concerns, most wireless power transfer (WPT) schemes utilize very low frequency, qu ... Full text Open Access Cite

Coded and compressive THz imaging with metamaterials

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2014 Imaging in long wavelength regimes holds huge potential in many fields, from security to skin cancer detection. However, it is often difficult to image at these frequencies - the so called 'THz gap1' is no exception. Current techniques generally involve me ... Full text Cite

Terahertz compressive imaging with metamaterial spatial light modulators

Journal Article Nature Photonics · January 1, 2014 Imaging at long wavelengths, for example at terahertz and millimetre-wave frequencies, is a highly sought-after goal of researchers because of the great potential for applications ranging from security screening and skin cancer detection to all-weather nav ... Full text Cite

Tunable plasmonic platform for giant fluorescence enhancement

Conference Optics InfoBase Conference Papers · January 1, 2014 We demonstrate a colloidally synthesized plasmonic platform for giant fluorescence enhancement and increased spontaneous emission rate of embedded fluorophores. A transition between fluorescence enhancement and quenching is revealed depending on the plasmo ... Cite

Experimental improvement of birefringence and response time in Liquid Crystals using surface preparation of polyimide at 20GHz

Journal Article IEEE MTT-S International Microwave Symposium Digest · January 1, 2014 This paper presents an experimental study analyzing the effects of surface treated Polyimide (PI) on dielectric anisotropy and response time of Liquid Crystal (LC) in an In-Plane Switching (IPS) cell design. A Co-Planar Waveguide (CPW) transmission line is ... Full text Cite

Tunable plasmonic platform for giant fluorescence enhancement

Conference Conference on Lasers and Electro-Optics Europe - Technical Digest · January 1, 2014 We demonstrate a colloidally synthesized plasmonic platform for giant fluorescence enhancement and increased spontaneous emission rate of embedded fluorophores. A transition between fluorescence enhancement and quenching is revealed depending on the plasmo ... Cite

A transparent meshed solar monopole antenna for UWB applications

Conference 8th European Conference on Antennas and Propagation, EuCAP 2014 · January 1, 2014 This paper demonstrates the integration of a transparent meshed circular monopole antenna with a polycrystalline silicon (poly-Si) solar cell operating as an RF ground plane in addition to its photovoltaic function. While the meshed circular monopole with ... Full text Cite

A dual-polarized solar cell stacked microstrip patch antenna with a λ/4 DC/RF isolation circuit for 5.8 GHz band WiMAX networks

Conference 8th European Conference on Antennas and Propagation, EuCAP 2014 · January 1, 2014 In this paper, photovoltaic integration of a dual-polarized microstrip patch antenna is demonstrated for 5.8 GHz band WiMAX networks. The proposed antenna consists of a dual-fed ±45° dual-polarized square microstrip patch stacked with a polycrystalline sil ... Full text Cite

An outline of indirect holographic methods for antenna measurements and microwave imaging

Conference 2014 24th International Conference Radioelektronika, RADIOELEKTRONIKA 2014 - Proceedings · January 1, 2014 Indirect microwave holographic techniques offer a simple, low cost technique for a range of microwave measurements including the determination of antenna characteristics and the ability to provide good quality images of passive objects. This work provides ... Full text Cite

Microwave imaging using indirect holographic techniques

Journal Article IEEE Antennas and Propagation Magazine · January 1, 2014 This work describes how indirect holographic techniques, previously applied to the determination of antenna radiation patterns, can be adapted for the imaging of passive objects. It provides details of how complex scattered field values can be obtained in ... Full text Cite

A novel RF excited plasma cathode electron beam gun design

Journal Article IEEE Transactions on Electron Devices · January 1, 2014 This paper presents a new radio frequency (RF) excited plasma cathode electron beam (EB) gun design and experimental results at a frequency of 84 MHz. The design offers the following benefits over thermionic cathode triode EB guns: much longer cathode life ... Full text Cite

Characterisation of an RF excited argon plasma cathode electron beam gun

Conference 2014 10th International Vacuum Electron Sources Conference, IVESC 2014 and 2nd International Conference on Emission Electronics, ICEE 2014 - Proceedings · January 1, 2014 This work describes the experimental set up used for carrying out spectroscopic measurements in a plasma cathode electron beam (EB) gun. Advantages of plasma cathode guns over thermionic guns are described. The factors affecting electron beam power such as ... Full text Cite

Spectroscopic characterization of a novel RF excited plasma cathode electron beam gun design

Conference IEEE International Vacuum Electronics Conference, IVEC 2014 · January 1, 2014 This work presents a radio frequency (RF) excited electron beam (EB) gun design and experimental results obtained at a frequency of 84 MHz. Details of the design features of the plasma device are given and advantages over thermionic cathode triode EB guns ... Full text Cite

Forward and backward unidirectional scattering from plasmonic coupled wires.

Journal Article Optics express · December 2013 We analyze the resonant electromagnetic response of sub-wavelength plasmonic dimers formed by two silver strips separated by a thin dielectric spacer and embedded in a uniform dielectric media. We demonstrate that the off-resonant electric and resonant, ge ... Full text Cite

Imaging of diffuse objects with dispersive imagers

Journal Article International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz · December 1, 2013 Dispersive imagers measure multiple speckle realizations of the object to be estimated. This poses a challenge for coherent imaging as classically objects are backpropagated and then despeckled. We present initial findings on an intensity based method for ... Full text Cite

Simulations of 2D metamaterial apertures for coherent computational imaging

Conference 2013 IEEE International Conference on Microwaves, Communications, Antennas and Electronic Systems, COMCAS 2013 · December 1, 2013 A metamaterial aperture operating as a leaky waveguide with resonating metamaterial irises can sweep its operation frequency to modify its complex field pattern with no moving parts. By randomly distributing the metamaterials' resonance frequencies, we sho ... Full text Cite

Adjustable metamaterial cloaking using an elastic crystal

Journal Article Asia-Pacific Microwave Conference Proceedings, APMC · December 1, 2013 We introduce a microwave cloak composed of smart metamaterials whose electromagnetic properties can be effectively changed by mechanical deformation. Against mechanical deformations, our smart metamaterials self-adjust own flexible elasto-electromagnetic c ... Full text Cite

Visual illustrations of microwave holographic beamforming using a modulated surface-impedance metamaterial

Journal Article IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · December 1, 2013 We demonstrate the use of a metamaterial to transition between a guided surface mode and a designed radiative aperture distribution. Plots of the field distribution at incremental distances removed from the aperture plane illustrate the transformation from ... Full text Cite

Effective nonlinearities in metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2013 Clever structuring of dielectric and metallic composites can lead to effective electric, magnetic and anisotropic responses. When hybridized with nonlinear components, such 'metamaterials' can support a wide range of nonlinear properties characterized by e ... Cite

Circular dichroism of four-wave mixing in nonlinear metamaterials

Journal Article Physical Review B - Condensed Matter and Materials Physics · November 25, 2013 Metamaterial engineering offers a route to combine unusual and interesting optical phenomena in ways that are rare or nonexistent in nature. As an exploration of this wide parameter space, we experimentally demonstrate strong cross-phase modulation and fou ... Full text Cite

Metamaterial polarization multiplexed gratings

Journal Article CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013 · November 21, 2013 We demonstrate a metamaterial grating that has two diffraction periods for two orthogonal linear polarization states of illuminations. The proposed method will be useful in free space optical communications and novel optical imaging systems. © OSA 2013. ... Cite

Solar cell stacked dual-polarised patch antenna for 5.8 GHz band WiMAX network

Journal Article Electronics Letters · November 21, 2013 A novel combination of a two-port slant ± 45° dual-polarised microstrip patch antenna with a polycrystalline silicon (poly-Si) solar cell operating as an RF stacked parasitic patch element is presented and discussed for 5.8 GHz band polarisation diverse mu ... Full text Cite

Surfaces, films, and multilayers for compact nonlinear plasmonics

Journal Article Journal of the Optical Society of America B: Optical Physics · November 1, 2013 We present a step-by-step analysis of four-wave mixing (FWM) in one-dimensional stacks of metallo-dielectric structures, pointing out various channels of plasmonic and Fabry-Perot enhancement. We start from the derivation of oblique incidence FWM at a sing ... Full text Cite

Homogenization analysis of complementary waveguide metamaterials

Journal Article Photonics and Nanostructures - Fundamentals and Applications · November 1, 2013 We analyze the properties of complementary metamaterials as effective inclusions patterned into the conducting walls of metal waveguide structures. We show that guided wave metamaterials can be homogenized using the same retrieval techniques used for volum ... Full text Cite

Measurements and simulations of low-wavenumber pedestal turbulence in the National Spherical Torus Experiment

Journal Article Nuclear Fusion · November 1, 2013 Previous pedestal turbulence measurements in the National Spherical Torus Experiment assessed the spatial and temporal properties of turbulence in the steep gradient region of H-mode pedestals during edge localized mode (ELM)-free, MHD-quiescent periods. H ... Full text Cite

Arbitrary birefringent metamaterials for holographic optics at λ = 1.55 μm.

Journal Article Optics express · November 2013 This paper presents an optical element capable of multiplexing two diffraction patterns for two orthogonal linear polarizations, based on the use of non-resonant metamaterial cross elements. The metamaterial cross elements provide unique building blocks fo ... Full text Cite

Quasi-analytic study of scattering from optical plasmonic patch antennas

Journal Article Journal of Applied Physics · October 28, 2013 We present an analytical treatment of the optical scattering from film-coupled nanocubes. Film-coupled nanoparticles are a convenient platform for the demonstration of a variety of fundamental plasmonic phenomena, including nonlocality and field enhancemen ... Full text Cite

Overview of physics results from the conclusive operation of the National Spherical Torus Experiment

Journal Article Nuclear Fusion · October 1, 2013 Research on the National Spherical Torus Experiment, NSTX, targets physics understanding needed for extrapolation to a steady-state ST Fusion Nuclear Science Facility, pilot plant, or DEMO. The unique ST operational space is leveraged to test physics theor ... Full text Cite

Effects of classical nonlocality on the optical response of three-dimensional plasmonic nanodimers

Journal Article Journal of the Optical Society of America B: Optical Physics · October 1, 2013 We examine the optical scattering from a variety of axially symmetric plasmonic nanoparticle dimers separated by nanoscale gaps, quantifying the role of classical nonlocality on their optical properties. Due to the rotational symmetry of the analyzed struc ... Full text Cite

Progress in characterization of the pedestal stability and turbulence during the edge-localized-mode cycle on National Spherical Torus Experiment

Journal Article Nuclear Fusion · September 1, 2013 Progress in characterizing the edge stability and properties of the microinstabilities responsible for enhanced transport in the pedestal region is reported. The stability of the pedestal is characterized in high performance discharges on National Spherica ... Full text Cite

Subwavelength plasmonics for graded-index optics on a chip.

Journal Article Optics letters · September 2013 Planar plasmonic devices are becoming attractive for myriad applications, owing to their potential compatibility with standard microelectronics technology and the capability for densely integrating a large variety of plasmonic devices on a chip. Mitigating ... Full text Cite

Solar cell stacked modified Z-double L-slot quad-band PIFA

Conference 2013 7th European Conference on Antennas and Propagation, EuCAP 2013 · August 14, 2013 This paper proposes a novel low-profile quad-band multifunctional solar PIFA consisting of a polycrystalline silicon (poly-Si) solar cell stacked suspended modified radiating element with Z and double L-slots. The measured return loss (S11) and E-plane/H-p ... Cite

The use of indirect holographic techniques for microwave imaging

Conference Proceedings of 13th Conference on Microwave Techniques, COMITE 2013 - MAREW 2013: Microwave and Radio Electronics Week 2013 · August 12, 2013 The use of indirect holographic techniques for antenna testing has been shown to offer a simple, low cost scalar technique for the reconstruction of complex antenna aperture fields. This work extends the use of indirect holography to the imaging of objects ... Full text Cite

Cross-coax fed wideband solar patch antenna

Conference Proceedings of 13th Conference on Microwave Techniques, COMITE 2013 - MAREW 2013: Microwave and Radio Electronics Week 2013 · August 12, 2013 In this paper, a cross-coax fed low-profile short-circuited suspended patch antenna combined with a polycrystalline silicon (poly-Si) solar cell operating as a radiating patch element is proposed for self-powered 2.4 GHz band WLAN and 2.3/2.5 GHz band WiMA ... Full text Cite

Electron-scale turbulence spectra and plasma thermal transport responding to continuous e × B shear ramp-up in a spherical tokamak

Journal Article Nuclear Fusion · August 1, 2013 Microturbulence is considered to be a major candidate in driving anomalous transport in fusion plasmas, and the equilibrium E × B shear generated by externally driven flow can be a powerful tool to control microturbulence in future fusion devices such as F ... Full text Cite

Metamaterial apertures for coherent computational imaging on the physical layer.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · August 2013 We introduce the concept of a metamaterial aperture, in which an underlying reference mode interacts with a designed metamaterial surface to produce a series of complex field patterns. The resonant frequencies of the metamaterial elements are randomly dist ... Full text Cite

Lower poling thresholds and enhanced Pockels coefficients in nanoparticle-polymer composites

Journal Article Applied Physics Letters · July 15, 2013 We investigate computationally the electromagnetic response of composite media made from high-aspect ratio nanoparticle arrays. The shape and local ordering of the nanoparticles can be used to both confine and enhance the local electric fields induced in r ... Full text Cite

Investigations of resolution limits for indirect microwave holographic imaging

Conference International Journal of RF and Microwave Computer-Aided Engineering · July 1, 2013 This work describes how indirect holography which has previously been applied to the determination of antenna radiation patterns can be adapted for the imaging of passive objects. It provides details of how complex scattered field values can be obtained in ... Full text Cite

Nanophotonics: Optical time reversal with graphene

Journal Article Nature Physics · July 1, 2013 Would you ever guess that a microscopic flake of graphite could reverse the diffraction of light? An experiment that demonstrates just such an effect highlights the exciting optical applications of graphene — an atomic layer of carbon with a two-dimensiona ... Full text Open Access Cite

Two-dimensional reconfigurable gradient index memory metasurface

Journal Article Applied Physics Letters · June 3, 2013 Creation and control of spatial gradients in electromagnetic properties is a central theme underlying optical device design. In this work, we demonstrate that through modification of the spatial and temporal distribution of current, we can obtain increased ... Full text Cite

Characterization and parametric dependencies of low wavenumber pedestal turbulence in the National Spherical Torus Experiment

Journal Article Physics of Plasmas · May 1, 2013 The spherical torus edge region is among the most challenging regimes for plasma turbulence simulations. Here, we measure the spatial and temporal properties of ion-scale turbulence in the steep gradient region of H-mode pedestals during edge localized mod ... Full text Cite

Thin low-loss dielectric coatings for free-space cloaking.

Journal Article Optics letters · May 2013 We report stereolithographic polymer-based fabrication and experimental operation of a microwave X-band cloaking device. The device is a relatively thin (about one wavelength thick) shell of an air-dielectric composite, in which the dielectric component ha ... Full text Open Access Cite

A solar cell stacked multi-slot quad-band PIFA for GSM, WLAN and WiMAX networks

Journal Article IEEE Microwave and Wireless Components Letters · April 30, 2013 This letter presents a novel low-profile quad-bandsolar PIFA which has the potential to be employed in self-powered low-power GSM 1800, 2.4 GHz band WLAN and 2.3/3.3/5.8 GHz band WiMAX networks. The multi-slot loaded radiating PIFA element consisting of W- ... Full text Cite

UWB meshed solar monopole antenna

Journal Article Electronics Letters · April 25, 2013 A novel combination of a parametrically optimised UWB meshed circular disc monopole antenna with a polycrystalline silicon (poly-Si) solar cell is presented and discussed. The results indicate that the fabricated meshed solar monopole antenna operates acro ... Full text Cite

Hydrodynamic model for plasmonics: a macroscopic approach to a microscopic problem.

Journal Article Chemphyschem : a European journal of chemical physics and physical chemistry · April 2013 In this concept, we present the basic assumptions and techniques underlying the hydrodynamic model of electron response in metals and demonstrate that the model can be easily incorporated into computational models. We discuss the role of the additional bou ... Full text Cite

Far-field analysis of axially symmetric three-dimensional directional cloaks.

Journal Article Optics express · April 2013 Axisymmetric radiating and scattering structures whose rotational invariance is broken by non-axisymmetric excitations present an important class of problems in electromagnetics. For such problems, a cylindrical wave decomposition formalism can be used to ... Full text Open Access Cite

Flight experience of the xilinx virtex-4

Journal Article IEEE Transactions on Nuclear Science · March 26, 2013 This paper provides information regarding the use of the Xilinx Virtex-4 field-programmable gate array (FPGA) in a spacecraft deployed to low-earth orbit. The results are compared to pre-deployment accelerated single-event effects (SEEs) and fault-injectio ... Full text Cite

Nonlinear interference and unidirectional wave mixing in metamaterials.

Journal Article Physical review letters · February 2013 When both electric and magnetic mechanisms contribute to a particular nonlinear optical process, there exists the possibility for nonlinear interference, often characterized by constructive or destructive interference in the radiation pattern of harmonics ... Full text Cite

Impact of nonlocal response on metallodielectric multilayers and optical patch antennas

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 2, 2013 We analyze the impact of nonlocality on the waveguide modes of metallodielectric multilayers and optical patch antennas, the latter formed from metal strips closely spaced above a metallic plane. We model both the nonlocal effects associated with the condu ... Full text Cite

Dielectric metamaterials and composites in the age of 3D printing, and directional cloaking

Journal Article 2013 7th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics, METAMATERIALS 2013 · January 1, 2013 The rapid evolution of additive manufacturing techniques has the potential to revolutionize a wide range of fabrication-limited fields. In this article, we apply plastic additive manufacturing to the creation of radio-frequency electromagnetic devices, dem ... Full text Cite

Metamaterial polarization multiplexed gratings

Journal Article 2013 Conference on Lasers and Electro-Optics, CLEO 2013 · January 1, 2013 We demonstrate a metamaterial grating that has two diffraction periods for two orthogonal linear polarization states of illuminations. The proposed method will be useful in free space optical communications and novel optical imaging systems. © 2013 The Opt ... Full text Cite

A report on H-FSO/RF antenna measurement for outdoor applications

Conference Proceedings of the 2013 2nd International Workshop on Optical Wireless Communications, IWOW 2013 · January 1, 2013 This paper presents a report on experimental set up and results for a hybrid free space optics (FSO)/radio frequency (RF) dual purpose antenna for outdoor applications. The basic design of the antenna is discussed and we present two sets of early experimen ... Full text Cite

Printed slot loaded bow-tie antenna with super wideband radiation characteristics for imaging applications

Journal Article IEEE Transactions on Antennas and Propagation · January 1, 2013 A super wideband printed modified bow-tie antenna loaded with rounded-T shaped slots fed through amicrostrip balun is proposed for microwave and millimeter-wave band imaging applications. The modified slot-loaded bow-tie pattern increases the electrical le ... Full text Cite

Early stage breast cancer detection using indirect microwave holography

Journal Article Progress in Electromagnetics Research · January 1, 2013 A novel microwave imaging approach for early stage breast cancer detection is described. The proposed technique involves the use of an Indirect Microwave Holographic technique employing a patented synthetic reference wave. This approach offers benefits in ... Full text Cite

Investigation of transformer turns ratio between feed and slot of aperture coupled slot antenna by using S11 parameter

Journal Article IEEE Transactions on Antennas and Propagation · January 1, 2013 This communication presents a simplified design approach to obtain the turns ratio Nf which models the coupling between the microstrip feed and slot line of an aperture coupled slot antenna by using the S11 parameter. Equations are derived using S11 parame ... Full text Cite

A solar cell stacked slot-loaded suspended microstrip patch antenna with multiband resonance characteristics for wlan and WiMAX systems

Journal Article Progress in Electromagnetics Research · January 1, 2013 In this paper, a novel self-complementary shaped multiple- L slot loaded suspended microstrip patch antenna stacked with a polycrystalline silicon (poly-Si) solar cell is presented for 2.4/5.2GHz band WLAN and 2.5/3.3/5.8 GHz band WiMAX networks. While the ... Full text Cite

Observation of ion scale fluctuations in the pedestal region during the edge-localized-mode cycle on the National Spherical Torus Experiment

Journal Article Physics of Plasmas · January 1, 2013 Characterization of the spatial structure of turbulence fluctuations during the edge localized mode cycle in the pedestal region is reported. Using the beam emission spectroscopy and the correlation reflectometry systems, measurements show spatial structur ... Full text Cite

A full-parameter unidirectional metamaterial cloak for microwaves.

Journal Article Nature materials · January 2013 Invisibility is a notion that has long captivated the popular imagination. However, in 2006, invisibility became a practical matter for the scientific community as well, with the suggestion that artificially structured metamaterials could enable a new elec ... Full text Cite

Metamaterial apertures for computational imaging.

Journal Article Science (New York, N.Y.) · January 2013 By leveraging metamaterials and compressive imaging, a low-profile aperture capable of microwave imaging without lenses, moving parts, or phase shifters is demonstrated. This designer aperture allows image compression to be performed on the physical hardwa ... Full text Cite

Homogenization analysis of complementary waveguide metamaterials

Journal Article Photonics and Nanostructures - Fundamentals and Applications · 2013 Cite

Plasmonic waveguide modes of film-coupled metallic nanocubes.

Journal Article Nano letters · January 2013 A metallic nanoparticle positioned over a metal film offers great advantages as a highly controllable system relevant for probing field-enhancement and other plasmonic effects. Because the size and shape of the gap between the nanoparticle and film can be ... Full text Cite

On-orbit results for the xilinx virtex-4 FPGA

Conference IEEE Radiation Effects Data Workshop · December 11, 2012 This paper provides information regarding the use of the Xilinx Virtex-4 field-programmable gate array in a spacecraft deployed to low-earth orbit. The results are compared to pre-deployment accelerated and fault-injection testing. Copyright © 2012 by the ... Full text Cite

Design of a highly efficient wideband suspended solar array antenna

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · December 10, 2012 This paper presents the design of a wideband suspended solar patch array antenna for WLAN and ISM band applications. The suspended silicon solar cells, which have been replaced with traditional microstrip patches and work as antennas within the design, are ... Full text Cite

Defining new optics with metamaterials

Journal Article 2012 Conference on Lasers and Electro-Optics, CLEO 2012 · December 6, 2012 Metamaterials provide resources for the development of unconventional optical devices and the improvement of conventional ones. We review the methods of analyzing, constructing and characterizing metamaterials, and discuss their extension to infrared and v ... Cite

Plasmonic graded-index planar lens based on subwavelength features in the effective index regime

Journal Article 2012 Conference on Lasers and Electro-Optics, CLEO 2012 · December 6, 2012 We experimentally demonstrate the planar focusing of Surface Plasmon Polaritons using space variant PMMA subwavelength features on top of a metallic film. Focusing is obtained by creating an effective graded refractive index profile. © 2012 OSA. ... Cite

Infrared metamaterial hologram

Journal Article Optics InfoBase Conference Papers · December 1, 2012 We designed, fabricated, and characterized an infrared metamaterial hologram. The hologram correctly reproduces the design image. This work demonstrates that metamate-rials can be used to fabricate devices with arbitrary 2D refractive index profiles. © 201 ... Cite

Plasmonic graded-index planar lens based on subwavelength features in the effective index regime

Journal Article Optics InfoBase Conference Papers · December 1, 2012 We experimentally demonstrate the planar focusing of Surface Plasmon Polaritons using space variant PMMA subwavelength features on top of a metallic film. Focusing is obtained by creating an effective graded refractive index profile. © OSA 2012. ... Cite

Defining new optics with metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2012 Metamaterials provide resources for the development of unconventional optical devices and the improvement of conventional ones. We review the methods of analyzing, constructing and characterizing metamaterials, and discuss their extension to infrared and v ... Cite

A triband short-circuited suspended solar patch antenna

Conference 2012 10th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2012 · December 1, 2012 In this paper, a triband low-profile short-circuited suspended patch antenna combined with a polycrystalline silicon solar cell working as a radiating patch element is proposed for 2.3/2.5/2.8/3.3/3.5 GHz band WiMAX and 2.4 GHz band WLAN networks. The fabr ... Full text Cite

Symmetric/asymmetric H-plane horn fed offset parabolic reflector antenna with switchable pencil/fan-beam radiation characteristics

Conference 2012 10th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2012 · December 1, 2012 This paper presents a modified offset parabolic reflector antenna design with easily switchable pencil/fan-beam radiation patterns for X-band tracking, scanning and surveillance microwave radar systems. The modified offset parabolic reflector antenna, comb ... Full text Cite

A meshed multiband solar patch array antenna

Conference LAPC 2012 - 2012 Loughborough Antennas and Propagation Conference · December 1, 2012 In this paper, a meshed multiband solar patch array antenna, consisting of a polycrystalline silicon solar panel working as a ground plane whilst generating a DC power output of 1.48 W as a result of the photovoltaic effect with a measured solar efficiency ... Full text Cite

Effect of gamma radiation on potential ionising radiation detectors and dosimeters based on quantum dots

Conference IEEE Nuclear Science Symposium Conference Record · December 1, 2012 In this work, we report measured effects on the fluorescent emission spectra of commercially produced core-shell (CdSe/ZnS) quantum dots (QDs) of 2.5 nm, 3.3 nm and 6.3 nm size in toluene, following exposure to 1 MeV gamma irradiation in the range 0.1-110 ... Full text Cite

Development of a laboratory based XRF facility for measuring elemental abundance ratios in planetary analogue powder samples

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2012 This paper describes the use of a swept-charge device (SCD) silicon X-ray detector in a laboratory based X-ray fluorescence (XRF) facility for calculating elemental abundance ratios from planetary analogue powder samples. The facility was developed to supp ... Full text Cite

The effects of radiation damage on the spectral resolution of the Chandrayaan-1 X-ray Spectrometer over the full mission duration

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2012 The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device silicon X-ray detectors providing a total collect ... Full text Cite

Controlled-reflectance surfaces with film-coupled colloidal nanoantennas.

Journal Article Nature · December 2012 Efficient and tunable absorption is essential for a variety of applications, such as designing controlled-emissivity surfaces for thermophotovoltaic devices, tailoring an infrared spectrum for controlled thermal dissipation and producing detector elements ... Full text Cite

Development of an ionising radiation detector based on quantum dots absorbed in porous glass

Conference Proceedings of the IEEE Conference on Nanotechnology · November 22, 2012 In this work, we report measured effects on the fluorescent emission spectra of commercially produced core-shell (CdSe/ZnS) quantum dots (QDs). We report the effects on the fluorescent emission spectra of commercially produced CdSe/ZnS QDs of 2.5 nm, 3.3 n ... Full text Cite

Modelling and analysis of a smart antenna system with sub-sector dynamic capacity enhancement for mobile telecommunication networks

Conference Proceedings of the 2012 8th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2012 · November 12, 2012 This paper describes the modelling and analysis of a new smart antenna concept. The paper outlines the rational for the development of a dynamically reconfigurable smart antenna system without greatly increasing the complexity of the system. The subject sm ... Full text Cite

A solar parabolic reflector antenna design for digital satellite communication systems

Conference Proceedings of the 2012 8th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2012 · November 12, 2012 This paper introduces a compact solar parabolic reflector antenna design, with an effective DC solar performance and high gain / pencil beam antenna radiation characteristics, as an alternative to the standalone use of home-based autonomous solar panels an ... Full text Cite

Flow stabilization with active hydrodynamic cloaks.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · November 2012 We demonstrate that fluid flow cloaking solutions, based on active hydrodynamic metamaterials, exist for two-dimensional flows past a cylinder in a wide range of Reynolds numbers (Re's), up to approximately 200. Within the framework of the classical Brinkm ... Full text Open Access Cite

Low-loss directional cloaks without superluminal velocity or magnetic response.

Journal Article Optics letters · November 2012 The possibility of making an optically large (many wavelengths in diameter) object appear invisible has been a subject of many recent studies. Exact invisibility scenarios for large (relative to the wavelength) objects involve (meta)materials with superlum ... Full text Open Access Cite

Quantitative comparison of gradient index and refractive lenses.

Journal Article Journal of the Optical Society of America. A, Optics, image science, and vision · November 2012 We analyze the Seidel wavefront aberrations and spot sizes of gradient index (GRIN) singlet lenses with Δn≈1. We consider and compare curved and planar GRIN lenses with F-numbers of 5 and 1 against equivalent refractive lenses. We find that the planar GRIN ... Full text Cite

Optics: Nanotube holograms.

Journal Article Nature · November 2012 Full text Cite

Diagnostic performance of the beam emission spectroscopy system on the National Spherical Torus Experiment

Conference Review of Scientific Instruments · October 1, 2012 The beam emission spectroscopy system on the National Spherical Torus Experiment measures localized density fluctuations on the ion gyroscale. Optical sightlines provide core to edge radial coverage, and the sightlines are aligned to typical pitch angles t ... Full text Cite

Plasmon ruler with angstrom length resolution.

Journal Article ACS nano · October 2012 We demonstrate a plasmon nanoruler using a coupled film nanoparticle (film-NP) format that is well-suited for investigating the sensitivity extremes of plasmonic coupling. Because it is relatively straightforward to functionalize bulk surface plasmon suppo ... Full text Cite

Second-harmonic generation in metallic nanoparticles: Clarification of the role of the surface

Journal Article Physical Review B - Condensed Matter and Materials Physics · September 27, 2012 We present a numerical investigation of the second-order nonlinear optical properties of metal-based metamaterial nanoresonators. The nonlinear optical response of the metal is described by a hydrodynamic model, with the effects of electron pressure in the ... Full text Cite

Current oscillations in vanadium dioxide: Evidence for electrically triggered percolation avalanches

Journal Article Physical Review B - Condensed Matter and Materials Physics · September 17, 2012 In this work, we experimentally and theoretically explore voltage-controlled oscillations occurring in microbeams of vanadium dioxide. These oscillations are a result of the reversible insulator-to-metal phase transition in vanadium dioxide. By examining t ... Full text Cite

Nonlinear magnetoelectric metamaterials: Analysis and homogenization via a microscopic coupled-mode theory

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · September 12, 2012 Artificially structured metamaterials hybridized with elements that respond nonlinearly to incident electromagnetic fields can, from a macroscopic perspective, support nonlinear responses that cannot be described by purely electric or magnetic interactions ... Full text Cite

Electronically reconfigurable metal-on-silicon metamaterial

Journal Article Physical Review B - Condensed Matter and Materials Physics · August 8, 2012 Reconfigurable metamaterial-based apertures can play a unique role in both imaging and in beam-forming applications, where current technology relies mostly on the fabrication and integration of large detector or antenna arrays. Here, we report the experime ... Full text Open Access Cite

Transformation optics and subwavelength control of light.

Journal Article Science (New York, N.Y.) · August 2012 Our intuitive understanding of light has its foundation in the ray approximation and is intimately connected with our vision. As far as our eyes are concerned, light behaves like a stream of particles. We look inside the wavelength and study the properties ... Full text Cite

Probing the ultimate limits of plasmonic enhancement.

Journal Article Science (New York, N.Y.) · August 2012 Metals support surface plasmons at optical wavelengths and have the ability to localize light to subwavelength regions. The field enhancements that occur in these regions set the ultimate limitations on a wide range of nonlinear and quantum optical phenome ... Full text Open Access Cite

Demonstration of nonlinear magnetoelectric coupling in metamaterials

Journal Article Applied Physics Letters · July 30, 2012 We demonstrate nonlinear magnetoelectric coupling in a varactor-loaded metamaterial at microwave frequencies. The nonlinear magnetoelectric coupling takes the form of second-harmonic generation in which incident magnetic fields at frequency ω drive an elec ... Full text Cite

An overview of the theory and applications of metasurfaces: The two-dimensional equivalents of metamaterials

Journal Article IEEE Antennas and Propagation Magazine · July 17, 2012 Metamaterials are typically engineered by arranging a set of small scatterers or apertures in a regular array throughout a region of space, thus obtaining some desirable bulk electromagnetic behavior. The desired property is often one that is not normally ... Full text Cite

The effect of protons on the performance of second generation Swept Charge Devices

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · July 11, 2012 The e2v technologies Swept Charge Device (SCD) was developed as a large area detector for X-ray Fluorescence (XRF) analysis, achieving near Fano-limited spectroscopy at -15 °C. The SCD was flown in the XRF instruments onboard the European Space Agency's SM ... Full text Cite

A modified holographic technique for cylindrical near-field antenna measurements

Conference Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012 · July 2, 2012 A modification of the synthetic-cylindrical-wave-based holographic technique for determining radiation patterns and aperture fields of antennas is proposed. The modification is based on using both the sum and difference of the near field and reference sign ... Full text Cite

The use of swept-charge devices in planetary analogue X-ray fluorescence studies

Conference Journal of Instrumentation · July 1, 2012 The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device (SCD) silicon X-ray detectors providing a total c ... Full text Cite

Construction of invisibility cloaks of arbitrary shape and size using planar layers of metamaterials

Journal Article Journal of Applied Physics · June 15, 2012 Transformation optics (TO) is a powerful tool for the design of electromagnetic and optical devices with novel functionality derived from the unusual properties of the transformation media. In general, the fabrication of TO media is challenging, requiring ... Full text Open Access Cite

Reconciliation of generalized refraction with diffraction theory.

Journal Article Optics letters · June 2012 When an electromagnetic wave is obliquely incident on the interface between two homogeneous media with different refractive indices, the requirement of phase continuity across the interface generally leads to a shift in the trajectory of the wave. When a l ... Full text Cite

Performance of a three dimensional transformation-optical-flattened Lüneburg lens.

Journal Article Optics express · June 2012 We demonstrate both the beam-forming and imaging capabilities of an X-band (8-12 GHz) operational Lüneburg lens, one side of which has been flattened via a coordinate transformation optimized using quasi-conformal transformation optics (QCTO) procedures. O ... Full text Cite

Origin of second-harmonic generation enhancement in optical split-ring resonators

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 15, 2012 We present a study of the second-order nonlinear optical properties of metal-based metamaterials. A hydrodynamic model for electronic response is used, in which nonlinear surface contributions are expressed in terms of the bulk polarization. The model is i ... Full text Cite

Design of a highly efficient beam scanning asymmetric H-plane horn antenna

Conference 2012 IEEE International Workshop on Antenna Technology, iWAT 2012 · May 11, 2012 This paper presents the design and results of a novel asymmetric H-plane horn antenna with an easily scanable, highly efficient asymmetric radiation pattern. This design offers a cost-effective and practical alternative to the current beam scanning horn an ... Full text Cite

A smart antenna system with sub-sector dynamic capacity enhancement for mobile telecommunication networks

Conference 2012 IEEE International Workshop on Antenna Technology, iWAT 2012 · May 11, 2012 Dynamic concentration of the users within a part of a cell sector has placed pressure on network operators to find ways to dynamically optimise the sector to increase capacity and quality of service while maintaining coverage. Smart antenna systems have be ... Full text Cite

Characterization of high order modes of plasmonic antenna formed by nanoparticle/thin film hybrid structures

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · May 4, 2012 The plasmonic modes of a nano-antenna formed by a nanoparticle/thin film hybrid system are investigated. Plasmonic nano-antennas are well-known for their capabilities to concentrate electromagnetic wave into extreme small region and couple the emission fro ... Full text Open Access Cite

Experimental study of parametric dependence of electron-scale turbulence in a spherical tokamak

Journal Article Physics of Plasmas · May 1, 2012 Electron-scale turbulence is predicted to drive anomalous electron thermal transport. However, experimental study of its relation with transport is still in its early stage. On the National Spherical Tokamak Experiment (NSTX), electron-scale density fluctu ... Full text Cite

Suppressing electron turbulence and triggering internal transport barriers with reversed magnetic shear in the National Spherical Torus Experiment

Journal Article Physics of Plasmas · May 1, 2012 The National Spherical Torus Experiment (NSTX) [M. Ono, Nucl. Fusion 40, 557 (2000)] can achieve high electron plasma confinement regimes that are super-critically unstable to the electron temperature gradient driven (ETG) instability. These plasmas, dubbe ... Full text Cite

Enhancing four-wave-mixing processes by nanowire arrays coupled to a gold film.

Journal Article Optics express · May 2012 We consider the process of four-wave mixing in an array of gold nanowires strongly coupled to a gold film. Using full-wave simulations, we perform a quantitative comparison of the four-wave mixing efficiency associated with a bare film and films with nanow ... Full text Cite

Probing dynamically tunable localized surface plasmon resonances of film-coupled nanoparticles by evanescent wave excitation.

Journal Article Nano letters · April 2012 The localized surface plasmon resonance (LSPR) spectrum associated with a gold nanoparticle (NP) coupled to a gold film exhibits extreme sensitivity to the nanogap region where the fields are tightly localized. The LSPR of an ensemble of film-coupled NPs c ... Full text Cite

Magnetic superlens-enhanced inductive coupling for wireless power transfer

Journal Article Journal of Applied Physics · March 15, 2012 We investigate numerically the use of a negative-permeability perfect lens for enhancing wireless power transfer between two current carrying coils. The negative permeability slab serves to focus the flux generated in the source coil to the receiver coil, ... Full text Open Access Cite

Infrared metamaterial phase holograms.

Journal Article Nature materials · March 2012 As a result of advances in nanotechnology and the burgeoning capabilities for fabricating materials with controlled nanoscale geometries, the traditional notion of what constitutes an optical device continues to evolve. The fusion of maturing low-cost lith ... Full text Cite

Isotropic-medium three-dimensional cloaks for acoustic and electromagnetic waves

Journal Article Journal of Applied Physics · March 1, 2012 We propose a generalization of the two-dimensional eikonal-limit cloak derived from a conformal transformation to three dimensions. The proposed cloak is a spherical shell composed of only isotropic media; it operates in the transmission mode and requires ... Full text Open Access Cite

Analytically describing the temperature-dependent constitutive parameters of an electromagnetic metamaterial

Journal Article Journal of Intelligent Material Systems and Structures · March 1, 2012 Analogous to mechanical systems, modeling the electromagnetic (EM) performance of large and complex metamaterial structures requires the use of effective-medium/constitutive properties. Constitutive properties are critical for efficiently bridging the gap ... Full text Cite

Using a discrete dipole approximation to predict complete scattering of complicated metamaterials

Journal Article New Journal of Physics · March 1, 2012 We develop a numerical technique for simulating metamaterial electromagnetic response based on an adaptation of the discrete dipole approximation (DDA). Our approach reduces each constituent metamaterial element within the composite to a point dipole with ... Full text Cite

Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances

Journal Article Physical Review B - Condensed Matter and Materials Physics · February 27, 2012 We propose that macroscopic objects built from negative-permeability metamaterials may experience resonantly enhanced magnetic force in low-frequency magnetic fields. Resonant enhancement of the time-averaged force originates from magnetostatic surface res ... Full text Open Access Cite

Measuring plasma turbulence using low coherence microwave radiation

Journal Article Applied Physics Letters · February 20, 2012 Low coherence backscattering (LCBS) is a proposed diagnostic technique for measuring plasma turbulence and fluctuations. LCBS is an adaptation of optical coherence tomography, a biomedical imaging technique. Calculations and simulations show LCBS measureme ... Full text Cite

The Chandrayaan-1 X-ray Spectrometer: First results

Conference Planetary and Space Science · January 1, 2012 We present X-ray fluorescence observations of the lunar surface, made by the Chandrayaan-1 X-ray Spectrometer during two solar flare events early in the mission (12th December 2008 and 10th January 2009). Modelling of the X-ray spectra with an abundance al ... Full text Cite

Investigation of a transient energetic charge exchange flux enhancement ('spike-on-tail') observed in neutral-beam-heated H-mode discharges in the National Spherical Torus Experiment

Journal Article Nuclear Fusion · January 1, 2012 In the National Spherical Torus Experiment (NSTX), a large increase in the charge exchange neutral flux localized around the neutral beam (NB) injection full energy is measured using a neutral particle analyser. Termed the high-energy feature (HEF), it app ... Full text Cite

Planar, flattened Luneburg lens at infrared wavelengths.

Journal Article Optics express · January 2012 Employing artificially structured metamaterials provides a means of circumventing the limits of conventional optical materials. Here, we use transformation optics (TO) combined with nanolithography to produce a planar Luneburg lens with a flat focal surfac ... Full text Cite

Broadband electromagnetic cloaking with smart metamaterials.

Journal Article Nature communications · January 2012 The ability to render objects invisible with a cloak that fits all objects and sizes is a long-standing goal for optical devices. Invisibility devices demonstrated so far typically comprise a rigid structure wrapped around an object to which it is fitted. ... Full text Open Access Cite

Raman antenna formed by molecule/plasmonic nanostructure hybrid system

Journal Article Optics InfoBase Conference Papers · December 1, 2011 A nano-antenna composed of a particle and a polarizable surface provides control of the spatial distribution and high enhancement of Raman scattering. This structure may serve as a stable platform for single molecule detection. © 2010 Optical Society of Am ... Cite

Metamaterial blazed gratings

Journal Article Optics InfoBase Conference Papers · December 1, 2011 We design, fabricate, and test a graded index diffractive structure based on non-resonant I-beam metamaterials. The measured diffraction spectrum is in good agreement with simulation, and suggests a path toward metamaterial based diffractive optics. © OSA/ ... Cite

Quasi-phase matching in nonlinear metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2011 We employ nonlinear metamaterials to demonstrate alternative quasi-phase matching (QPM) methods not feasible in natural materials. Additionally, we propose a method for dynamic QPM via resonance tuning, allowing for a tunable frequency of operation. © OSA/ ... Cite

Plasmonic nanocomposits for enhanced four-wave mixing generation

Journal Article Optics InfoBase Conference Papers · December 1, 2011 Third-order nonlinear response and strong field enhancement in gold nanocomposites are utilized to analyze the enhanced effective nonlinear susceptibility, subwavelength field confinement and reduced bend radii in the evanescent and propagating regimes of ... Cite

Quasi-phase matching in nonlinear metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2011 We employ nonlinear metamaterials to demonstrate alternative quasi-phase matching (QPM) methods not feasible in natural materials. Additionally, we propose a method for dynamic QPM via resonance tuning, allowing for a tunable frequency of operation. © OSA/ ... Cite

Three-wave mixing in microwave nonlinear metamaterial

Journal Article Optics InfoBase Conference Papers · December 1, 2011 We present a quantitative analysis of a three-wave mixing process in a microwave nonlinear metamaterial showing a good agreement between the analytical predictions and the experiment. Strong resonant nonlinear response is observed. © 2010 Optical Society o ... Cite

Quasi-phase matching in nonlinear metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2011 We employ nonlinear metamaterials to demonstrate alternative quasi-phase matching (QPM) methods not feasible in natural materials. Additionally, we propose a method for dynamic QPM via resonance tuning, allowing for a tunable frequency of operation. © OSA/ ... Cite

Controlling nonlinearity with structured metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2011 Artificially structured media can exhibit a wider range of both linear and nonlinear electromagnetic properties than are supported in conventional media. We discuss the design techniques and impact of these new emerging nonlinear metamaterials. © 2011 OSA. ... Cite

Controlling Gigahertz and Terahertz Surface ElectromagneticWaves with Metamaterial Resonators

Journal Article Physical Review X · December 1, 2011 We computationally and experimentally investigate the use of metamaterial resonators as bandpass filters and other components that enable control of guided surface electromagnetic waves. The guided surface electromagnetic wave propagates on a planar Goubau ... Full text Cite

Guest editorial: Special cluster on metamaterials

Journal Article IEEE Antennas and Wireless Propagation Letters · December 1, 2011 Full text Cite

Analysis of a gradient index metamaterial blazed diffraction grating

Journal Article IEEE Antennas and Wireless Propagation Letters · December 1, 2011 The equivalent of a blazed diffraction grating can be formed from an array of metamaterial elements arranged so as to produce a linear gradient in the effective refractive index. By spreading the gradient over a multiwavelength distance, and repeating the ... Full text Cite

Quantitative study of the enhancement of bulk nonlinearities in metamaterials

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · November 2, 2011 Artificially structured metamaterials offer a means to enhance the weak optical nonlinearities of natural materials. The enhancement results from the inhomogeneous nature of the metamaterial unit cell, over which the local field distribution can likewise b ... Full text Cite

Design and fabrication of a metamaterial gradient index diffraction grating at infrared wavelengths.

Journal Article Optics express · November 2011 We demonstrate the design, fabrication and characterization of an artificially structured, gradient index metamaterial with a linear index variation of Δn ~ 3.0. The linear gradient profile is repeated periodically to form the equivalent of a blazed gratin ... Full text Cite

Overcoming phase mismatch in nonlinear metamaterials [Invited]

Journal Article Optical Materials Express · November 1, 2011 Nonlinear metamaterials have potentially interesting applications in highly efficient wave-mixing and parametric processes, owing to their ability to combine enhanced nonlinearities with exotic and configurable linear properties. However, the strong disper ... Full text Cite

Planetary X-ray fluorescence analogue laboratory experiments and an elemental abundance algorithm for C1XS

Journal Article Planetary and Space Science · October 1, 2011 We have conducted laboratory experiments as an analogue to planetary XRF (X-ray fluorescence) missions in order to investigate the role of changing incidence (and phase) angle geometry and sample grain-size on the intensity of XRF from regolith-like sample ... Full text Cite

Overview of physics results from NSTX

Journal Article Nuclear Fusion · September 1, 2011 In the last two experimental campaigns, the low aspect ratio NSTX has explored physics issues critical to both toroidal confinement physics and ITER. Experiments have made extensive use of lithium coatings for wall conditioning, correction of non-axisymmet ... Full text Cite

Raman antenna formed by molecule/plasmonic nanostructure hybrid system

Journal Article 2011 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO 2011 · September 1, 2011 A nano-antenna composed of a particle and a polarizable surface provides control of the spatial distribution and high enhancement of Raman scattering. This structure may serve as a stable platform for single molecule detection. © 2011 OSA. ... Cite

Metamaterial blazed gratings

Journal Article 2011 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO 2011 · September 1, 2011 We design, fabricate, and test a graded index diffractive structure based on non-resonant I-beam metamaterials. The measured diffraction spectrum is in good agreement with simulation, and suggests a path toward metamaterial based diffractive optics. © 2011 ... Cite

Simulation of complex plasmonic circuits including bends.

Journal Article Optics express · September 2011 Using a finite-element, full-wave modeling approach, we present a flexible method of analyzing and simulating dielectric and plasmonic waveguide structures as well as their mode coupling. This method is applied to an integrated plasmonic circuit where a st ... Full text Cite

Quasi-phase matching in nonlinear metamaterials

Journal Article 2011 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO 2011 · September 1, 2011 We employ nonlinear metamaterials to demonstrate alternative quasi-phase matching (QPM) methods not feasible in natural materials. Additionally, we propose a method for dynamic QPM via resonance tuning, allowing for a tunable frequency of operation. © 2011 ... Cite

Three-wave mixing in microwave nonlinear metamaterial

Journal Article 2011 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO 2011 · September 1, 2011 We present a quantitative analysis of a three-wave mixing process in a microwave nonlinear metamaterial showing a good agreement between the analytical predictions and the experiment. Strong resonant nonlinear response is observed. © 2011 OSA. ... Cite

"Beam-emission spectroscopy" diagnostics also measure edge fast-ion light

Journal Article Plasma Physics and Controlled Fusion · August 1, 2011 Beam-emission spectroscopy (BES) diagnostics normally detect fluctuations in the light emitted by an injected neutral beam. Under some circumstances, however, light from fast ions that charge exchange in the high neutral-density region at the edge of the p ... Full text Cite

Fluid flow control with transformation media.

Journal Article Physical review letters · August 2011 We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations and physically implemented with anisotropic porous m ... Full text Open Access Cite

Controlling the second harmonic in a phase-matched negative-index metamaterial.

Journal Article Physical review letters · August 2011 Nonlinear metamaterials have been predicted to support new and exciting domains in the manipulation of light, including novel phase-matching schemes for wave mixing. Most notable is the so-called nonlinear-optical mirror, in which a nonlinear negative-inde ... Full text Open Access Cite

Reconfigurable gradient index using VO2 memory metamaterials

Journal Article Applied Physics Letters · July 25, 2011 We demonstrate tuning of a metamaterial device that incorporates a form of spatial gradient control. Electrical tuning of the metamaterial is achieved through a vanadium dioxide layer which interacts with an array of split ring resonators. We achieved a sp ... Full text Cite

Broadly tunable quasi-phase-matching in nonlinear metamaterials

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · July 21, 2011 The ability to tune the quasi-phase-matching (QPM) frequency is a highly desirable though lacking feature of many nonlinear devices. To this end, we consider QPM in a special class of active nonlinear metamaterials (MMs), whose properties can be controlled ... Full text Cite

Transformation optics compressed rotman lens implemented with complementary metamaterials

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · July 13, 2011 The solutions to the Rotman lens design equations constrain the minimum size of the device. Here we use Transformation Optics to compress a transmission line based Rotman lens by 27 percent along the optical axis while maintaining the beam steering range, ... Full text Cite

Impedance and complex power of radiating elements under electromagnetic source transformation

Journal Article Microwave and Optical Technology Letters · July 1, 2011 Transformation optics is a methodology that has proven useful in the design of complex media used to alter and control electromagnetic waves in either passive space or regions that contain source distributions. Recently it has been shown that the applicati ... Full text Cite

Metamaterial-enhanced coupling between magnetic dipoles for efficient wireless power transfer

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 18, 2011 Nonradiative coupling between conductive coils is a candidate mechanism for wireless energy transfer applications. In this paper we propose a power relay system based on a near-field metamaterial superlens and present a thorough theoretical analysis of thi ... Full text Open Access Cite

Wave mixing in nonlinear magnetic metacrystal

Journal Article Applied Physics Letters · May 16, 2011 We present experimental measurements of three- and four-wave mixing phenomena in an artificially structured nonlinear magnetic metacrystal at microwave frequencies. The sum frequency generation signal for the varactor-loaded split-ring resonator (VLSRR) me ... Full text Cite

Density gradient stabilization of electron temperature gradient driven turbulence in a spherical tokamak

Journal Article Physical Review Letters · April 22, 2011 In this Letter we report the first clear experimental observation of density gradient stabilization of electron temperature gradient driven turbulence in a fusion plasma. It is observed that longer wavelength modes, kρs10, are most stabilized by density gr ... Full text Cite

Nonlinear oscillator metamaterial model: numerical and experimental verification.

Journal Article Optics express · April 2011 We verify numerically and experimentally the accuracy of an analytical model used to derive the effective nonlinear susceptibilities of a varactor-loaded split ring resonator (VLSRR) magnetic medium. For the numerical validation, a nonlinear oscillator mod ... Full text Open Access Cite

Equivalent circuit analysis of metamaterial strain-dependent effective medium parameters

Journal Article Journal of Applied Physics · April 1, 2011 In this paper, we analytically describe the strain-dependent effective medium properties for a metamaterial electric-LC (ELC) resonator, commonly used in metamaterial designs to provide a tailored electric response to electromagnetic waves. Combining an eq ... Full text Cite

Identification of microtearing modes below the ion gyroscale in the National Spherical Torus Experiment

Journal Article Plasma Physics and Controlled Fusion · March 1, 2011 Gyrokinetic calculations indicate microtearing modes below the ion gyroscale are linearly unstable in a National Spherical Torus Experiment (NSTX) plasma. The modes are robustly unstable with respect to simulation parameters, radial location and discharge ... Full text Cite

Electromagnetic Enhancement Effect Caused by Aggregation on SERS-Active Gold Nanoparticles

Journal Article Plasmonics · March 1, 2011 We report a morphology-correlated surface-enhanced Raman scattering (SERS) from molecules on the surface of individual clusters of gold nanoparticles of two types and compare the signal from clusters of two, three, four, and five nanoparticles with the sig ... Full text Cite

Suppression of electron temperature gradient turbulence via negative magnetic shear in NSTX

Journal Article Physical Review Letters · February 3, 2011 Negative magnetic shear is found to suppress electron turbulence and improve electron thermal transport for plasmas in the National Spherical Torus Experiment (NSTX). Sufficiently negative magnetic shear results in a transition out of a stiff profile regim ... Full text Cite

Effect of gamma radiation on potential ionising radiation detectors and dosimeters based on quantum dots

Conference IEEE Nuclear Science Symposium Conference Record · January 1, 2011 The fluorescent quantum yield of core-shell (CdSe/ZnS) quantum dots (QDs) in hexane has recently been shown to decrease with increasing gamma irradiation dose. Here we report the effects on the fluorescent emission spectra of commercially produced CdSe/ZnS ... Full text Cite

Cross-section comparisons of cloaks designed by transformation optical and optical conformal mapping approaches

Journal Article Journal of Optics · January 1, 2011 We review several approaches to optical invisibility designed using transformation optics (TO) and optical conformal mapping (CM) techniques. TO is a general framework for solving inverse scattering problems based on mimicking spatial coordinate transforma ... Full text Open Access Cite

Design and experimental characterization of nonlinear metamaterials

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 2011 We apply an analytic theory [New J. Phys. 12, 093010 (2010)] toward the design of varactor-loaded split-ring resonator metacrystals, having nonlinear electromagnetic properties on demand. The design methodology here is shown to be efficient and is validate ... Full text Cite

Electromagnetic design with transformation optics

Journal Article Proceedings of the IEEE · January 1, 2011 Transformation optics is an emerging technique for the design of advanced electromagnetic media. Transformation optical devices exploit the form invariance of Maxwell's equations, allowing geometry to play the dominant role in the design process rather tha ... Full text Cite

Perfect relay lens at microwave frequencies based on flattening a Maxwell lens

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 2011 We consider the design and implementation of a two-dimensional metamaterial relay lens, conceptually formed by flattening a Maxwell fisheye lens-a perfect imaging device-through the use of a coordinate transformation. Because Maxwell's equations are form-i ... Full text Cite

Broadband wide angle lens implemented with dielectric metamaterials.

Journal Article Sensors (Basel, Switzerland) · January 2011 The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by a focal surface that is spherical and thus difficult to integrate with standard planar ... Full text Cite

The use of indirect holographic techniques for microwave imaging

Conference 2010 10th Mediterranean Microwave Symposium, MMS 2010 · December 20, 2010 This work provides a brief outline of the basic theory of indirect microwave holography. This is supported by experimental work which illustrates how this technique can be used successfully in a number of areas including antenna measurements, concealed wea ... Full text Cite

Preface

Chapter · December 1, 2010 Full text Cite

Broadband and low-loss non-resonant metamaterials

Journal Article · December 1, 2010 Loss and bandwidth have been major problems that limit the potential applications on metamaterials for a long time. To bring the ultimate opportunity to metamaterials, we analyze and discuss, in this chapter, another type of metamaterials that perform at l ... Full text Cite

Experiments and applications of metamaterials in microwave regime

Journal Article · December 1, 2010 In this chapter some experiments and applications of metamaterials in the microwave regime have been presented. Although metamaterials are composed of structures with finite periodicity, they can still be regarded as effective medium when the periodicity i ... Full text Cite

General theory on artificial metamaterials

Journal Article · December 1, 2010 In this chapter, we present a general theory of effective media to establish the relationship between the local field responses on metamaterial structure and the macroscopical behaviors for artificial metamaterials composed of periodic resonant structures. ... Full text Cite

Metamaterials: Theory, design, and applications

Journal Article Metamaterials: Theory, Design, and Applications · December 1, 2010 Metamaterials: Theory, Design and Applications focuses on the most recent research activity in metamaterials, taking a reader beyond previously covered areas like left-handed materials (LHM) and negative index materials (LIM). Some new developments covered ... Full text Cite

Experiment on cloaking devices

Journal Article · December 1, 2010 In this chapter, we will discuss the approach of utilizing transformation optic approach and metamaterial technology to construct various cloaking devices in experiment. We take the advantage of rapid design approach to demonstrate the reduced cloaking dev ... Full text Cite

Introduction to metamaterials

Journal Article · December 1, 2010 There have been increasing interests in metamaterials in the past 10 years in the scientific communities. However, metamaterials are sometimes regarded as left-handed materials or negative refractive index materials by a lot of people including researchers ... Full text Cite

Rapid design for metamaterials

Journal Article · December 1, 2010 Metamaterials are generally composed of sub-wavelength structures with designable geometries. The macroscopic properties of metamaterials are harnessed by engineering the geometric dimensions of the particles. During the past few years, designing metamater ... Full text Cite

Analysis of nonlinear electromagnetic metamaterials

Journal Article Optics InfoBase Conference Papers · December 1, 2010 We derive the expressions for the effective nonlinear susceptibilities of a metacrystal formed from resonant elements that couple strongly to the magnetic field. We experimentally illus-trate the accuracy and validity of our theoretical framework. © 2008 O ... Cite

Spectroscopic investigation of metamaterials across the effective medium threshold

Journal Article Metamaterials · December 1, 2010 We spectroscopically investigate the scaling properties of a metamaterial consisting of a square array of gold cylindrical dots. The electromagnetic response of the gold-dot array is found to scale in relation to the ratio of the incident wavelength over t ... Full text Cite

Integration of networks of sensors and electronics for structural health monitoring of composite materials

Journal Article Advances in Civil Engineering · December 1, 2010 The low-cost, widespread availability and robust nature of current electronic devices suggest the feasibility of creating a composite structure with integrated networked sensors to monitor in real time the life of civil and aerospace structures while in se ... Full text Cite

Preface

Journal Article Gastrointestinal Bleeding: A Practical Approach to Diagnosis and Management · December 1, 2010 Full text Cite

Multilayer W-band artificial dielectric on liquid crystal polymer

Journal Article IEEE Antennas and Wireless Propagation Letters · November 17, 2010 We present an artificial dielectric material designed to operate at W-band millimeter-wave frequencies. The artificial dielectric exhibits a wide range of variation in its effective refractive index, making it suitable for use in planar gradient index (GRI ... Full text Cite

A low profile radiating element with nearly hemispheric coverage for satellite communications on-the-move hybrid array antenna

Conference 2010 7th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2010 · November 12, 2010 A novel design solution of a dual-linearly-polarised Ku-band low-profile radiating element for low elevation angle coverage (down to 10° above horizon) is presented. Such an element is suitable for full-duplex Satellite Communications On-The-Move (SCOTM) h ... Cite

Parametric analysis of the strain-dependent behavior of a metamaterial electric resonator

Journal Article Applied Physics Letters · November 8, 2010 In this paper, we describe the strain-dependent behavior of an electric-LC (ELC) resonator unit cell, commonly used in metamaterial designs. We leverage analytic expression to understand the way strain manifests itself in a change in electromagnetic (EM) r ... Full text Open Access Cite

A synthetic diagnostic for validation of electron gyroradius scale turbulence simulations against coherent scattering measurements

Journal Article Physics of Plasmas · November 1, 2010 Comparison between spectra of short-scale density fluctuations measured with coherent electromagnetic scattering experiments and those extracted from space-resolved numerical simulations is affected by a number of systematic errors. These include the local ... Full text Cite

Designing three-dimensional transformation optical media using quasiconformal coordinate transformations.

Journal Article Physical review letters · November 2010 We introduce an approach to the design of three-dimensional transformation optical (TO) media based on a generalized quasiconformal mapping approach. The generalized quasiconformal TO (QCTO) approach enables the design of media that can, in principle, be b ... Full text Open Access Cite

Gold nanoparticles on polarizable surfaces as Raman scattering antennas.

Journal Article ACS nano · November 2010 Surface plasmons supported by metal nanoparticles are perturbed by coupling to a surface that is polarizable. Coupling results in enhancement of near fields and may increase the scattering efficiency of radiative modes. In this study, we investigate the Ra ... Full text Open Access Cite

Overview of the beam emission spectroscopy diagnostic system on the National Spherical Torus Experiment

Conference Review of Scientific Instruments · October 1, 2010 A beam emission spectroscopy (BES) system has been installed on the National Spherical Torus Experiment (NSTX) to study ion gyroscale fluctuations. The BES system measures Dα emission from a deuterium neutral heating beam. The system includes two optical v ... Full text Cite

Low-noise, high-speed detector development for optical turbulence fluctuation measurements for NSTX

Conference Review of Scientific Instruments · October 1, 2010 A new beam emission spectroscopy (BES) diagnostic is under development. Photon-noise limited measurements of neutral beam emissions are achieved using photoconductive photodiodes with a novel frequency-compensated broadband preamplifier. The new BES system ... Full text Cite

Ultrafast spectroscopy diagnostic to measure localized ion temperature and toroidal velocity fluctuations

Conference Review of Scientific Instruments · October 1, 2010 A dual-channel high-efficiency, high-throughput custom spectroscopic system has been designed and implemented at DIII-D to measure localized ion thermal fluctuations associated with drift wave turbulence. A large-area prism-coupled transmission grating and ... Full text Cite

Leveraging nanoscale plasmonic modes to achieve reproducible enhancement of light.

Journal Article Nano letters · October 2010 The strongly enhanced and localized optical fields that occur within the gaps between metallic nanostructures can be leveraged for a wide range of functionality in nanophotonic and optical metamaterial applications. Here, we introduce a means of precise co ... Full text Open Access Cite

Transformation optics with photonic band gap media.

Journal Article Physical review letters · October 2010 We introduce a class of optical media based on adiabatically modulated, dielectric-only, and potentially extremely low-loss, photonic crystals (PC). The media we describe represent a generalization of the eikonal limit of transformation optics (TO). The ba ... Full text Open Access Cite

Nonlinear long-range plasmonic waveguides

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · September 13, 2010 We report on plasmonic waveguides made of a thin metal stripe surrounded on one or both sides by a Kerr nonlinear medium. Using an iterative numerical method, we investigate the stationary long-range plasmons that exist for self-focusing and self-defocusin ... Full text Open Access Cite

The effects of radiation damage on the spectral resolution of the Chandrayaan-1 x-ray spectrometer

Conference Proceedings of SPIE - The International Society for Optical Engineering · September 7, 2010 The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device silicon X-ray detectors providing a total collect ... Full text Cite

Analysis of nonlinear electromagnetic metamaterials

Journal Article New Journal of Physics · September 6, 2010 We analyze the properties of a nonlinear metamaterial formed by integrating nonlinear components or materials into the capacitive regions of metamaterial elements. A straightforward homogenization procedure leads to general expressions for the nonlinear su ... Full text Cite

Enhancing imaging systems using transformation optics.

Journal Article Optics express · September 2010 We apply the transformation optical technique to modify or improve conventional refractive and gradient index optical imaging devices. In particular, when it is known that a detector will terminate the paths of rays over some surface, more freedom is avail ... Full text Open Access Cite

Nonlinear parameter retrieval from three- and four-wave mixing in metamaterials.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · September 2010 We present a generalized nonlinear susceptibility retrieval method for metamaterials based on transfer matrices and valid in the nondepleted pump approximation. We construct a general formalism to describe the transfer matrix method for nonlinear media and ... Full text Open Access Cite

Wide angle impedance matching metamaterials for waveguide-fed phased-array antennas

Journal Article IET Microwaves, Antennas and Propagation · August 1, 2010 This work investigates the gains realisable through the use of artificially structured materials, otherwise known as metamaterials, in the wide angle impedance matching (WAIM) of waveguide-fed phased-array antennas. The authors propose that the anisotropic ... Full text Cite

Acoustic cloaking transformations from attainable material properties

Journal Article New Journal of Physics · July 12, 2010 We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. The acoustic cloaks presented ... Full text Open Access Cite

Relaxation approach for the generation of inhomogeneous distributions of uniformly sized particles

Journal Article Applied Physics Letters · July 12, 2010 For many applications in gradient index devices and photonic crystals, it is necessary to be able to design semicrystalline distributions of particles where the lattice constant of the distribution is an arbitrary function of position. We propose a method ... Full text Open Access Cite

Experimental determination of the quadratic nonlinear magnetic susceptibility of a varactor-loaded split ring resonator metamaterial

Journal Article Applied Physics Letters · July 5, 2010 This letter presents a quantitative measurement of the second harmonic generated by a slab of varactor loaded split ring resonator metamaterial and the retrieval of the effective quadratic nonlinear magnetic susceptibility χ(2)musing an approach based on t ... Full text Open Access Cite

Development and characterization of healable carbon fiber composites with a reversibly cross linked polymer

Journal Article Journal of Composite Materials · June 1, 2010 Carbon fiber reinforced polymer (CFRP) laminates with remendable cross-linked polymeric matrices were fabricated using a modified resin transfer mold (RTM) technique. The healable composite resin, bis-maleimide tetrafuran (2MEP4F), was synthesized by mixin ... Full text Cite

Planar integrated optical detection of a hybrid long-range surface plasmon using an ingaas inverted-msm detector bonded to silicon

Journal Article IEEE Photonics Technology Letters · May 28, 2010 An InxGa1-x As thin-film inverted metalsemiconductormetal photodetector has been integrated with a gold hybrid long-range surface plasmon waveguide on silicon. This integrated structure enables planar integrated optical detection of a long-range surface pl ... Full text Cite

Scattering cross-section of a transformation optics-based metamaterial cloak

Journal Article New Journal of Physics · April 22, 2010 We present experimental quantitative scattering cross-section (SCS) measurements for a metamaterial cloak. The cloak is nearly identical to that reported in 2006; however, quantitative experimental measurements have not yet been reported for such a structu ... Full text Cite

Parametric oscillator based on a single-layer resonant metamaterial

Journal Article Optics Communications · April 15, 2010 We perform numerical simulations demonstrating parametric generation and oscillation processes in a single-layer of metamaterial composed of split ring resonators (SRRs). In general, a parametric resonance is achieved by introducing a time-modulation of on ... Full text Cite

A retrieval method for nonlinear metamaterials

Journal Article Optics Communications · April 15, 2010 Metamaterials are engineered periodic structures for which it is possible to assign effective homogenized constitutive properties. In recent years, metamaterials in which the constituent elements are integrated with inherently nonlinear materials or electr ... Full text Cite

Analysis of the power dependent tuning of a varactor-loaded metamaterial at microwave frequencies

Journal Article Applied Physics Letters · March 26, 2010 We present an analysis of the nonlinear, power-dependent resonance frequency shift for two metamaterial mediums consisting of arrays of varactor-loaded split ring resonators (VLSRRs). We confirm that, over a limited range of power, a VLSRR medium can be de ... Full text Open Access Cite

Analytic expressions for the constitutive parameters of magnetoelectric metamaterials.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · March 2010 Electromagnetic metamaterials are artificially structured media typically composed of arrays of resonant electromagnetic circuits, the dimension and spacing of which are considerably smaller than the free-space wavelengths of operation. The constitutive pa ... Full text Open Access Cite

Extreme-angle broadband metamaterial lens.

Journal Article Nature materials · February 2010 For centuries, the conventional approach to lens design has been to grind the surfaces of a uniform material in such a manner as to sculpt the paths that rays of light follow as they transit through the interfaces. Refractive lenses formed by this procedur ... Full text Cite

Fundamental issues in antenna design for microwave medical imaging applications

Conference 2010 7th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2010 · January 1, 2010 This paper surveys the development of microwave medical imaging and the fundamental challenges associated with microwave antennas design for medical imaging applications. Different microwave antennas used in medical imaging applications such as monopoles, ... Full text Cite

A Novel simplified mathematical model for antennas used in medical imaging applications

Conference Journal of Physics: Conference Series · January 1, 2010 In this paper a new technique is proposed to model the current across a monopole antenna and thereby the radiation fields of the antenna can be calculated. Generally, the Method of Moments (MOM) technique is used for this purpose whereby the integral equat ... Full text Cite

The effects of a finite ground plane on the characteristics of printed patch antennas with and without a suspended patch

Conference 2010 7th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2010 · January 1, 2010 In most analyses of microstrip patch antennas the effects of a finite ground plane are neglected because it is assumed infinite. However, in mobile communication systems the ground plane of antennas must be finite. Therefore, the effect of the finite groun ... Full text Cite

The Herschel -SPIRE instrument and its in-flight performance

Journal Article Astronomy and Astrophysics · January 1, 2010 The Spectral and Photometric Imaging REceiver (SPIRE), is the Herschel Space Observatory's submillimetre camera and spectrometer. It contains a three-band imaging photometer operating at 250, 350 and 500 μm, and an imaging Fourier-transform spectrometer (F ... Full text Cite

Simulation of MeV electron energy deposition in CdS quantum dots absorbed in silicate glass for radiation dosimetry

Conference Journal of Physics: Conference Series · January 1, 2010 We are currently developing 2D dosimeters with optical readout based on CdS or CdS/CdSe core-shell quantum-dots using commercially available materials. In order to understand the limitations on the measurement of a 2D radiation profile the 3D deposited ene ... Full text Cite

Calibration of the collective scattering system on NSTX

Conference 34th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2009 · December 31, 2009 A multichannel 280-GHz collective scattering system has been employed to investigate electron gyro-scale density fluctuations in National Spherical Torus Experiment (NSTX) plasmas. The longitudinal scattering volume length, which is the spatial resolution ... Full text Cite

Electron gyroscale fluctuation measurements in National Spherical Torus Experiment H-mode plasmas

Journal Article Physics of Plasmas · December 16, 2009 A collective scattering system has measured electron gyroscale fluctuations in National Spherical Torus Experiment [M. Ono, Nucl. Fusion 40, 557 (2000)] H-mode plasmas to investigate electron temperature gradient (ETG) turbulence. Observations and results ... Full text Cite

Planar integration of a long range surface plasmon waveguide with an inverted metal-semiconductor-metal photodetector on silicon

Journal Article Optics InfoBase Conference Papers · December 1, 2009 A long range surface plasmon polariton (LR-SPP) insulator-metal-insulator waveguide was integrated with a thin film InxGa1-xAs-based photodetector (PD) on silicon for planar detection of LR-SPPs, and demonstrated coupling from the LR-SPP to the PD. © 2009 ... Cite

A new low profile antenna with improved performance for satellite on-the-move communications

Conference Proceedings - 2009 3rd IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, MAPE 2009 · December 1, 2009 A novel design solution for a low-profile full-duplex Satellite-On-The-Move Communications hybrid scanned phased array antenna for low elevation angle coverage (down to 10° ) is described. The antenna is operated at Ku-Band. The unique louvered array eleme ... Full text Cite

Electromagnetic performance of mechanically loaded composite metamaterials

Journal Article ICCM International Conferences on Composite Materials · December 1, 2009 The field of metamaterials has seen tremendous advancements in the design, modeling, and development of structures with novel ElectroMagnetic (EM) properties. However, nothing had been done to characterize how those EM properties change when a metamaterial ... Cite

Development of self healing composite materials: Fabrication and micro-structural analyses

Journal Article ICCM International Conferences on Composite Materials · December 1, 2009 A custom resin transfer molding (RTM) method for the fabrication of carbon fiber composites using thermally reversible highly cross linked polymeric matrices was developed. The resulting material quality and healing efficiency was assessed using X-ray phas ... Cite

Design and analysis of three-dimensionalized ELC metamaterial unit cell

Journal Article IEEE Antennas and Wireless Propagation Letters · December 1, 2009 The use of a three-dimensional electric-LC (3D-ELC) resonator to obtain a minimally refractive and strongly transmissive composite metamaterial is explored. The 3D-ELC repeated unit cell consists of two ELC elements that, when put together, may be used to ... Full text Cite

Utilization of metamaterials for wide angle impedance matching (WAIM) in phased array antennas

Journal Article IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · November 16, 2009 Full text Cite

Planar integration of a long range surface plasmon waveguide with an inverted metal-semiconductor-metal photodetector on silicon

Journal Article 2009 Conference on Lasers and Electro-Optics and 2009 Conference on Quantum Electronics and Laser Science Conference, CLEO/QELS 2009 · November 16, 2009 A long range surface plasmon polariton (LR-SPP) insulator-metal-insulator waveguide was integrated with a thin film InxGa1-xAs-based photodetector (PD) on silicon for planar detection of LR-SPPs, and demonstrated coupling from the LR-SPP to the PD. ©2009 O ... Cite

High-frequency active metamaterials

Journal Article 2009 Conference on Lasers and Electro-Optics and 2009 Conference on Quantum Electronics and Laser Science Conference, CLEO/QELS 2009 · November 16, 2009 We present a systematic numerical study of metamaterials integrated with gain media to achieve composite metamaterials at terahertz and infrared wavelength with reduced losses. The impact of spatial dispersion on the effective permeability resonance restor ... Cite

Broadband gradient index microwave quasi-optical elements based on non-resonant metamaterials.

Journal Article Optics express · November 2009 Utilizing non-resonant metamaterial elements, we demonstrate that complex gradient index optics can be constructed exhibiting low material losses and large frequency bandwidth. Although the range of structures is limited to those having only electric respo ... Full text Cite

Millimeter-wave artificial dielectric gradient index lenses

Journal Article European Conference on Antennas and Propagation, EuCAP 2009, Proceedings · October 16, 2009 We present an artificial dielectric gradient index lens designed to operate at millimeter-wave frequencies. Finite element simulations are used in conjunction with material parameter retrieval techniques to design an artificial dielectric unit cell with an ... Cite

Educational card games

Journal Article Physics Education · September 23, 2009 A number of years have passed since the development of the 'Voyager: Satellites' educational card game reported in Physics Education in 2003. Since then, a large number of copies of the game have been produced and distributed across the UK, to a warm recep ... Full text Cite

Impurity transport studies in NSTX neutral beam heated H-mode plasmas

Journal Article Nuclear Fusion · September 21, 2009 The first experimental assessment of low-Z impurity transport in a neutral beam heated, high-confinement H-mode plasma sustained in a low-field, low-aspect ratio spherical tokamak, was performed at the National Spherical Torus Experiment (NSTX). The inject ... Full text Cite

Optical lens compression via transformation optics.

Journal Article Optics express · September 2009 Transformation optics is widely associated with the design of unconventional electromagnetic devices, such as electromagnetic cloaks or concentrators. However, a wide range of conventional optical devices with potentially advantageous properties can be des ... Full text Cite

Plasmonic multi-mode interference couplers.

Journal Article Optics express · September 2009 Plasmonic multi-mode interference (MMI) couplers have been investigated both numerically and experimentally at the telecommunication wavelength of 1.55 mum. In this study, the couplers are implemented using thin Au stripes that support long-range surface p ... Full text Cite

Memory metamaterials.

Journal Article Science (New York, N.Y.) · September 2009 The resonant elements that grant metamaterials their distinct properties have the fundamental limitation of restricting their useable frequency bandwidth. The development of frequency-agile metamaterials has helped to alleviate these bandwidth restrictions ... Full text Cite

Study of turbulent fluctuations driven by the electron temperature gradient in the National spherical torus experiment

Journal Article Nuclear Fusion · July 2, 2009 Various theories and numerical simulations support the conjecture that the ubiquitous problem of anomalous electron transport in tokamaks may arise from a short-scale turbulence driven by the electron temperature gradient. To check whether this turbulence ... Full text Cite

Electromagnetic source transformations using superellipse equations

Journal Article Applied Physics Letters · June 18, 2009 Transformation optics can be used to design media with unique properties that alter the behavior of electromagnetic waves in passive space and recently in space containing source distributions. We present source transformations where current from a linear ... Full text Cite

Internal transport barriers in the National Spherical Torus Experiment

Conference Physics of Plasmas · June 10, 2009 In the National Spherical Torus Experiment [M. Ono, Nucl. Fusion 41, 1435 (2001)], internal transport barriers (ITBs) are observed in reversed (negative) shear discharges where diffusivities for electron and ion thermal channels and momentum are reduced. W ... Full text Cite

Observations of reduced electron gyroscale fluctuations in national spherical torus experiment H-mode plasmas with large E×B flow shear

Journal Article Physical Review Letters · June 5, 2009 Electron gyroscale fluctuation measurements in National Spherical Torus Experiment H-mode plasmas with large toroidal rotation reveal fluctuations consistent with electron temperature gradient (ETG) turbulence. Large toroidal rotation in National Spherical ... Full text Cite

The use of automatic scale selection to improve the spatial and spectral resolution of a scintillator-coupled EMCCD

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · June 1, 2009 The technology behind the Electron-Multiplying Charge Coupled Device (EMCCD) was successfully exploited by e2v technologies in the late 1990s. Since then, many uses have been found for these low light level (L3) devices including surveillance and many scie ... Full text Cite

The X-ray quantum efficiency measurement of high resistivity CCDs

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · June 1, 2009 The CCD247 is the second generation of high-resistivity device to be manufactured in e2v technologies plc development programme. Intended for infrared astronomy, the latest devices are fabricated on high resistivity (∼8 kΩ cm) bulk silicon, allowing for a ... Full text Cite

The effect of protons on the performance of swept-charge devices

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · June 1, 2009 The e2v technologies CCD54, or swept-charge device (SCD) has been extensively radiation tested for use in the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument, to be launched as a part of the Indian Space Research Organisation (ISRO) Chandrayaan-1 payloa ... Full text Cite

Chandrayaan-1 X-ray Spectrometer (C1XS)-Instrument design and technical details

Journal Article Planetary and Space Science · June 1, 2009 The UK-built Chandrayaan-1 X-ray Spectrometer (C1XS) is flying as an ESA instrument on India's Chandrayaan-1 mission to the Moon. The Chandrayaan-1 mission launched on the 22nd October 2008 and entered a 100 km polar lunar orbit on the 12th November 2008. ... Full text Cite

The C1XS X-ray Spectrometer on Chandrayaan-1

Journal Article Planetary and Space Science · June 1, 2009 The Chandrayaan-1 X-ray Spectrometer (C1XS) is a compact X-ray spectrometer for the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission. It exploits heritage from the D-CIXS instrument on ESA's SMART-1 mission. As a result of detailed dev ... Full text Cite

An efficient broadband metamaterial wave retarder.

Journal Article Optics express · April 2009 Metamaterials with anisotropic electromagnetic properties have the capability to manipulate the polarization states of electromagnetic waves. We describe a method to design a broadband, low-loss wave retarder with graded constitutive parameter distribution ... Full text Cite

Design, theory, and measurement of a polarization-insensitive absorber for terahertz imaging

Journal Article Physical Review B - Condensed Matter and Materials Physics · March 3, 2009 We present the theory, design, and realization of a polarization- insensitive metamaterial absorber for terahertz frequencies. Effective-medium theory is used to describe the absorptive properties of the metamaterial in terms of optical constants-a descrip ... Full text Cite

Life testing of EMCCD gain characteristics

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · March 1, 2009 Two electron-multiplication, charge-coupled devices (e2v CCD97) were operated continuously for 52 days to assess their avalanche gain stability. This work was part of an evaluation study into their suitability for the radial velocity spectrometer (RVS) ins ... Full text Cite

Gradient index circuit by waveguided metamaterials

Journal Article Applied Physics Letters · February 27, 2009 Metamaterials are artificially structured materials that provide considerable flexibility for control of electromagnetic waves. The metamaterial concept can also be applied to the design of planar waveguiding structures. Here, we illustrate this design app ... Full text Cite

Experimental two-dimensional field mapping of total internal reflection lateral beam shift in a self-collimated photonic crystal

Journal Article Applied Physics Letters · February 23, 2009 A lateral beam shift is demonstrated both theoretically and in microwave experiments when total internal reflection takes place at the boundary of a self-collimating two-dimensional photonic crystal consisting of an array of high index dielectric cylinders ... Full text Cite

The Chandrayaan-1 X-ray spectrometer

Journal Article Current Science · February 1, 2009 The Chandrayaan-1 X-ray Spectrometer (C1XS) is a compact X-ray spectrometer for the Chandrayaan-1 lunar mission. It exploits heritage from the D-C1XS instrument on ESA's SMART-1 mission. C1XS is designed to measure absolute and relative abundances of major ... Cite

Hybrid resonant phenomena in a SRR/YIG metamaterial structure.

Journal Article Optics express · February 2009 We consider the hybridization of the resonance of a SRR metamaterial with the gyromagnetic material resonance of yittrium iron garnet (YIG) inclusions. The combination of an artificial structural resonance and natural material resonance generates a unique ... Full text Cite

Directional coupling between dielectric and long-range plasmon waveguides

Journal Article New Journal of Physics · January 16, 2009 We have designed, fabricated and characterized integrated directional couplers capable of converting the mode of an optical dielectric waveguide into a long-range plasmon propagating along a thin metal stripe. We demonstrate that the coupling between the t ... Full text Cite

High-frequency active metamaterials

Journal Article Optics InfoBase Conference Papers · January 1, 2009 We present a systematic numerical study of metamaterials integrated with gain media to achieve composite metamaterials at terahertz and infrared wavelength with reduced losses. The impact of spatial dispersion on the effective permeability resonance restor ... Cite

Broadband ground-plane cloak.

Journal Article Science (New York, N.Y.) · January 2009 The possibility of cloaking an object from detection by electromagnetic waves has recently become a topic of considerable interest. The design of a cloak uses transformation optics, in which a conformal coordinate transformation is applied to Maxwell's equ ... Full text Cite

Focus on cloaking and transformation optics

Journal Article New Journal of Physics · December 26, 2008 Full text Cite

Characterization of complementary electric field coupled resonant surfaces

Journal Article Applied Physics Letters · December 8, 2008 We present angle-resolved free-space transmission and reflection measurements of a surface composed of complementary electric inductive-capacitive (CELC) resonators. By measuring the reflection and transmission coefficients of a CELC surface with different ... Full text Cite

A modified holographic technique for antenna measurements

Conference ISAPE 2008 - The 8th International Symposium on Antennas, Propagation and EM Theory Proceedings · December 1, 2008 This work describes an extension to the use of indirect holographic techniques for antenna measurements. Previous versions of this work have been restricted to the measurement of high gain antennas without reducing sample spacing and increasing measurement ... Full text Cite

A multiple switched beam smart antenna with beam shaping for dynamic optimisation of capacity & coverage in mobile telecommunication networks

Conference ISAPE 2008 - The 8th International Symposium on Antennas, Propagation and EM Theory Proceedings · December 1, 2008 A four column Smart antenna array fed by a 4×4 Butler matrix augmented by a variable beam shaping network has been designed and simulated. It is demonstrated that using only three phase shifters within the beam shaping network provides dynamic beam flexibi ... Full text Cite

Radiation study of swept-charge devices for the Chandrayaan-1 X-ray spectrometer (C1XS) instrument

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2008 The Chandrayaan-1 X-ray Spectrometer (C1XS) will be launched as part of the Indian Space Research Organisation (ISRO) Chandrayaan-1 payload in September 2008, arriving at the Moon within 7 days to begin a two year mission in lunar orbit conducting mineralo ... Full text Cite

Imaging and spectroscopy using a scintillator-coupled EMCCD

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2008 The CCD97 is a low light level (L3) device from e2v technologies range of electron multiplying CCDs (EMCCDs). The device uses e2v's patented extended gain register and through the use of appropriately designed electrodes can be used to maximise the signal ... Full text Cite

A collective scattering system for measuring electron gyroscale fluctuations on the National Spherical Torus Experiment

Journal Article Review of Scientific Instruments · December 1, 2008 A collective scattering system has been installed on the National Spherical Torus Experiment (NSTX) to measure electron gyroscale fluctuations in NSTX plasmas. The system measures fluctuations with k⊥ ρ e 0.6 and k⊥ 20 cm-1. Up to five distinct wavenumbers ... Full text Cite

Optical source transformations.

Journal Article Optics express · December 2008 Transformation optics is a recently appreciated methodology for the design of complex media that control the propagation of electromagnetic and other types of waves. The transformation optical technique involves the use of coordinate transformations applie ... Full text Cite

Transformation-optical design of sharp waveguide bends and corners

Journal Article Applied Physics Letters · December 1, 2008 Transformation optics is a recently appreciated approach for designing complex electromagnetic media. Here, we describe the extension of transformation optical techniques to include waveguide boundary conditions. We illustrate the use of finite embedded co ... Full text Cite

Progress of metamaterials at microwave frequencies

Journal Article META08 - Proceedings of the 2008 International Workshop on Metamaterials · December 1, 2008 Metamaterials have been rapidly explored for a few years and attracted tremendous attentions. This paper discussed the latest progress in metamaterials at microwave frequencies. The ability of designing and building the complex medium has been dramatically ... Full text Cite

Random gradient index metamaterials

Journal Article META08 - Proceedings of the 2008 International Workshop on Metamaterials · December 1, 2008 We report a broadband reflectionless gradient random medium design and experimental implementation by using metamaterial technology. This gradient random medium matches the impedance of the air and gradually change its refraction index randomly, creating a ... Full text Cite

Invisibility cloak without singularity

Journal Article Applied Physics Letters · November 21, 2008 An elliptical invisible cloak is proposed using a coordinate transformation in the elliptical-cylindrical coordinate system, which crushes the cloaked object to a line segment instead of a point. The elliptical cloak is reduced to a nearly circular cloak i ... Full text Cite

A modified holographic technique for planar near-field antenna measurements

Journal Article IEEE Transactions on Antennas and Propagation · October 27, 2008 A modification of the synthetic-plane-wave-based holographic technique for determining radiation patterns and aperture fields of medium-gain horn antennas is proposed. The modification is based on using both the sum and difference of the near field and ref ... Full text Cite

Hybrid metamaterials enable fast electrical modulation of freely propagating terahertz waves

Journal Article Applied Physics Letters · September 15, 2008 We demonstrate fast electrical modulation of freely propagating terahertz waves at room temperature using hybrid metamaterial devices. The devices are planar metamaterials fabricated on doped semiconductor epitaxial layers, which form hybrid metamaterial-S ... Full text Cite

Dual-band planar electric THz metamaterial with resonator yield analysis

Journal Article Conference on Quantum Electronics and Laser Science (QELS) - Technical Digest Series · September 15, 2008 THz radiation transmission through a dual-band electric metamaterial is presented, where we analyze manufacturing defects in the metamaterial. Removing different resonator percentages allows us to quantify the effects of manufacturing defects on the materi ... Full text Cite

Dual-band planar electric THz metamaterial with resonator yield analysis

Journal Article 2008 Conference on Quantum Electronics and Laser Science Conference on Lasers and Electro-Optics, CLEO/QELS · September 15, 2008 THz radiation transmission through a dual-band electric metamaterial is presented, where we analyze manufacturing defects in the metamaterial. Removing different resonator percentages allows us to quantify the effects of manufacturing defects on the materi ... Full text Cite

Partial focusing by indefinite complementary metamaterials

Journal Article Physical Review B - Condensed Matter and Materials Physics · September 10, 2008 We have experimentally realized a two-dimensional partial focusing within a planar waveguide using complementary indefinite metamaterials. When the electric fields emitted from the dipole are TE polarized, the focusing condition requires negative magnetic ... Full text Cite

Electrically coupled graded index metamaterial

Journal Article Conference Proceedings 2008 IEEE International Workshop on Antenna Technology: Small Antennas and Novel Metamaterials, IWAT 2008 · September 1, 2008 Full text Cite

Distance-dependent plasmon resonant coupling between a gold nanoparticle and gold film.

Journal Article Nano letters · August 2008 We present an experimental analysis of the plasmonic scattering properties of gold nanoparticles controllably placed nanometers away from a gold metal film. We show that the spectral response of this system results from the interplay between the localized ... Full text Cite

Production of BABAR skimmed analysis datasets using the grid

Conference Journal of Physics: Conference Series · July 1, 2008 The BABAR Collaboration, based at Stanford Linear Accelerator Center (SLAC), Stanford, US, has been performing physics reconstruction, simulation studies and data analysis for 8 years using a number of compute farms around the world. Recent developments in ... Full text Cite

Transformation-optical design of adaptive beam bends and beam expanders.

Journal Article Optics express · July 2008 We describe the design of adaptive beam bends and beam splitters with arbitrary bend and split angles by use of finite embedded coordinate transformations. The devices do not exhibit reflection at the entrance or exit surfaces. It is shown that moderate an ... Full text Cite

Dynamic tuning of an infrared hybrid-metamaterial resonance using vanadium dioxide

Journal Article Applied Physics Letters · July 2008 We demonstrate a metamaterial device whose far-infrared resonance frequency can be dynamically tuned. Dynamic tuning should alleviate many bandwidth-related roadblocks to metamaterial application by granting a wide matrix of selectable electromagnetic prop ... Cite

Reconfigurable core-satellite nanoassemblies as molecularly-driven plasmonic switches

Journal Article Nano Letters · July 2008 Molecular control of plasmon coupling is investigated in sub-100 nm assemblies composed of 13 nm gold "satellite" particles tethered by reconfigurable DNA nanostructures to a 50 nm gold "core" particle. Reconfiguration of the DNA nanostructures from a comp ... Cite

Dual-band planar electric metamaterial in the terahertz regime.

Journal Article Optics express · June 2008 We present the design, fabrication, and measurement of a dual-band planar metamaterial with two distinct electric resonances at 1.0 and 1.2 THz, as a step towards the development of frequency agile or broadband THz materials and devices. A method of defini ... Full text Cite

Design of arbitrarily shaped concentrators based on conformally optical transformation of nonuniform rational B-spline surfaces

Journal Article Applied Physics Letters · June 2008 We study the design of arbitrarily shaped electromagnetic (EM) concentrators and their potential applications. To obtain closed-form formulas of EM parameters for an arbitrarily shaped concentrator, we employ nonuniform rational B-spline (NURBS) to represe ... Cite

Perfect metamaterial absorber.

Journal Article Physical review letters · May 2008 We present the design for an absorbing metamaterial (MM) with near unity absorbance A(omega). Our structure consists of two MM resonators that couple separately to electric and magnetic fields so as to absorb all incident radiation within a single unit cel ... Full text Cite

Design of electromagnetic cloaks and concentrators using form-invariant coordinate transformations of Maxwell's equations

Journal Article Photonics and Nanostructures - Fundamentals and Applications · April 1, 2008 The technique of applying form-invariant, spatial coordinate transformations of Maxwell's equations can facilitate the design of structures with unique electromagnetic or optical functionality. Here, we illustrate the transformation-optical approach in the ... Full text Cite

Preface

Journal Article Photonics and Nanostructures - Fundamentals and Applications · April 1, 2008 Full text Cite

Experimental comparison between conventional and hybrid long-range surface plasmon waveguide bends

Journal Article Physical Review A - Atomic, Molecular, and Optical Physics · February 25, 2008 We report on the characterization of long-range surface plasmon waveguide bends at telecom wavelengths (λ=1550 nm). The structures consist of a thin Au stripe embedded in a transparent polymer film. When the polymer thickness is larger than the lateral ex ... Full text Cite

Optical design of reflectionless complex media by finite embedded coordinate transformations.

Journal Article Physical review letters · February 2008 Transformation optics offers an unconventional approach to the control of electromagnetic fields. The transformation optical structures proposed to date, such as electromagnetic "invisibility" cloaks and concentrators, are inherently reflectionless and lea ... Full text Cite

Dual-band planar electric THz metamaterial with resonator yield analysis

Journal Article Optics InfoBase Conference Papers · January 1, 2008 THz radiation transmission through a dual-band electric metamaterial is presented, where we analyze manufacturing defects in the metamaterial. Removing different resonator percentages allows us to quantify the effects of manufacturing defects on the materi ... Cite

Dual-band planar electric THz metamaterial with resonator yield analysis

Journal Article Optics InfoBase Conference Papers · January 1, 2008 THz radiation transmission through a dual-band electric metamaterial is presented, where we analyze manufacturing defects in the metamaterial. Removing different resonator percentages allows us to quantify the effects of manufacturing defects on the materi ... Cite

Experimental demonstration of electromagnetic tunneling through an epsilon-near-zero metamaterial at microwave frequencies

Journal Article Physical Review Letters · January 2008 Silveirinha and Engheta have recently proposed that electromagnetic waves can tunnel through a material with an electric permittivity (epsilon) near zero (ENZ). An ENZ material of arbitrary geometry can thus serve as a perfect coupler between incoming and ... Cite

Scattering theory derivation of a 3D acoustic cloaking shell

Journal Article Physical Review Letters · January 2008 Through acoustic scattering theory we derive the mass density and bulk modulus of a spherical shell that can eliminate scattering from an arbitrary object in the interior of the shell-in other words, a 3D acoustic cloaking shell. Calculations confirm that ... Cite

Experimental demonstration of electromagnetic tunneling through an epsilon-near-zero metamaterial at microwave frequencies.

Journal Article Physical review letters · January 2008 Silveirinha and Engheta have recently proposed that electromagnetic waves can tunnel through a material with an electric permittivity (epsilon) near zero (ENZ). An ENZ material of arbitrary geometry can thus serve as a perfect coupler between incoming and ... Full text Cite

Scattering theory derivation of a 3D acoustic cloaking shell.

Journal Article Physical review letters · January 2008 Through acoustic scattering theory we derive the mass density and bulk modulus of a spherical shell that can eliminate scattering from an arbitrary object in the interior of the shell--in other words, a 3D acoustic cloaking shell. Calculations confirm that ... Full text Cite

Guiding light with long-range plasmons

Journal Article Optics and Photonics News · January 1, 2008 Long-range surface plasmons can be implemented, to develop integrated optical circuits and other chip-scale photonic applications. Long-range surface plasmons are optical modes propagating along metallic circuits at optical and near-infrared wavelengths th ... Full text Cite

Proton irradiation of swept-charge devices for the Chandrayaan-1 X-ray Spectrometer (C1XS)

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · December 21, 2007 This paper presents work carried out in support of swept-charge device (SCD) characterisation for the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument. A brief overview of the C1XS instrument is presented, followed by a description of SCD structure and o ... Full text Cite

Circuit verification of tunneling effect in zero permittivity medium

Journal Article Applied Physics Letters · December 14, 2007 We demonstrate the tunneling effect in zero permittivity medium using the multilayered printed circuit, where complementary split ring resonators have been used to produce the resonant electric response and achieve the effective zero permittivity near the ... Full text Cite

An improved holographic technique for medium-gain antenna near field measurements

Conference IET Seminar Digest · December 1, 2007 A modification of the holographic technique based on synthetic plane wave for determining radiation patterns and aperture fields of medium-gain horn antennas is proposed. The modification is based on using both the sum and difference of the near field and ... Full text Cite

Initial results on X-polar far-field radiation patterns prediction using indirect holographic measurements

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · December 1, 2007 Full text Cite

A modified holographic technique for antenna measurements

Conference 2007 International Conference on Electromagnetics in Advanced Applications, ICEAA'07 · December 1, 2007 A modification of the synthetic-plane-wave-based holographic technique for determining radiation patterns and aperture fields of medium-gain horn antennas is proposed. The modification is based on using both the sum and difference of the near field and ref ... Full text Cite

Characterisation of swept-charge devices for the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2007 The Indian Space Research Organisation (ISRO) Chandrayaan-1 mission is India's first lunar spacecraft, containing a suite of instruments to carry out high-resolution remote sensing of the Moon at visible, near infrared and X-ray wavelengths. Due for launch ... Full text Cite

Applications of metamaterials in the GHz frequency domain

Journal Article IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · December 1, 2007 Full text Cite

Optical control of metamaterial unit cells at microwave frequencies

Journal Article Conference Proceedings of the International Symposium on Signals, Systems and Electronics · December 1, 2007 We have developed metamaterial unit cells whose properties can be controlled dynamically using near-infrared light. The structures consist of split ring resonators (SRRs) operating at microwave frequencies that contain a piece of low-doped silicon in their ... Full text Cite

The role of metamaterials and plasmons for novel sensing applications

Journal Article Proceedings of IEEE Sensors · December 1, 2007 The past ten years have seen a tremendous acceleration in the exploration of metals for photonic applications. This exploration has been common to both the metamaterials and the plasmonics fields, which leverage the strong resonances of structured metals t ... Full text Cite

Isotropic frequency selective surfaces made of cubic resonators

Journal Article Applied Physics Letters · November 19, 2007 Isotropic frequency selective surface (FSS) made of cubic arrangements of split ring resonators (SRRs) is proposed and analyzed. For this purpose, a suitable isotropic modification of the SRR was used in the design of a cubic unit element invariant under t ... Full text Cite

Characterizing the effects of disorder in metamaterial structures

Journal Article Applied Physics Letters · October 31, 2007 We investigate the effects of disorder on metamaterial samples composed of split ring resonators with randomly introduced variation in their geometrical dimensions. We demonstrate that disorder broadens the negative permeability band and introduces effecti ... Full text Cite

Transformation-designed optical elements.

Journal Article Optics express · October 2007 We describe transformation design of optical elements which, in addition to image transfer, perform useful operations. For one class of operations, including translation, rotation, mirroring and inversion, an image can be generated that is ideal in the sen ... Full text Cite

Numerical simulations of long-range plasmonic transmission lines

Journal Article Springer Series in Optical Sciences · September 26, 2007 Structures that guide waves can be found in almost every optoelectronic or photonic device. Yet, the basic principles of guided waves in practical realizations have not evolved substantially over the past several decades. At microwave or radio frequencies ... Full text Cite

Realization of a super waveguide for high-power-density generation and transmission using right- and left-handed transmission-line circuits

Journal Article Physical Review E · September 2007 In an earlier work [Cheng and Cui, Phys. Rev. B 72, 113112 (2005)], we have shown theoretically that extremely high power densities can be generated and transmitted in a super waveguide which is filled with homogeneous bilayers of right- and left-handed ma ... Cite

Tuned permeability in terahertz split-ring resonators for devices and sensors

Journal Article Applied Physics Letters · August 17, 2007 A process is demonstrated for tuning the magnetic resonance frequency of a fixed split-ring resonator array, by way of adding material near the split-ring elements. Applying drops of a silicon-nanospheres/ethanol solution to the surface of the sample decre ... Full text Cite

Negative index material composed of electric and magnetic resonators

Journal Article Applied Physics Letters · August 2, 2007 Negative index-of-refraction materials (NIMs) require both the electric permittivity and the magnetic permeability of the material to be negative. Most reported NIMs have combined conducting split ring resonators (SRRs) to realize the magnetic response and ... Full text Cite

Simulations of hybrid long-range plasmon modes with application to 90 degree bends.

Journal Article Optics letters · August 2007 We perform rigorous simulations of hybrid long-range modes guided by a central metal core and a two-dimensional dielectric slab. We show that these modes are subject to fewer limitations than conventional long-range plasmon modes in terms of field confinem ... Full text Cite

Description and explanation of electromagnetic behaviors in artificial metamaterials based on effective medium theory.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · August 2007 We present a general theory of effective media to set up the relationship between the particle responses and the macroscopic system behaviors for artificial metamaterials composed of periodic resonant structures. By treating the unit cell of the periodic s ... Full text Cite

Negative index and indefinite media waveguide couplers

Journal Article Applied Physics A: Materials Science and Processing · May 1, 2007 We study the coupling interaction between dielectric waveguides and coupling elements made from negative-refracting media. The coupling configuration consists of a length of dielectric waveguide, which terminates either directly into or near a planar layer ... Full text Cite

Electromagnetic characterization of planar metamaterials by oblique angle spectroscopic measurements

Journal Article Physical Review B - Condensed Matter and Materials Physics · March 13, 2007 Artificially structured metamaterials with unit-cell dimensions on the order of 1 10th of a wavelength (λ 10) have been shown to be well approximated by an effective medium description which mimics a continuous material. In this paper we present data for t ... Full text Cite

Resonant crystal band gap metamaterials in the microwave regime and their exotic amplification of evanescent waves

Journal Article Applied Physics Letters · March 9, 2007 The authors realize resonant crystal band gap metamaterials (CBMs) using circuit structures in the microwave regime, which behave quite differently from the conventional photonic band gap structures. They show that a periodic array of series inductor and s ... Full text Cite

Indirect holographic techniques for determining antenna radiation characteristics and imaging aperture fields

Journal Article IEEE Antennas and Propagation Magazine · February 1, 2007 Indirect holographic techniques offer the potential of using simple and inexpensive near-field intensity-pattern measurements for the determination of the radiation characteristics of microwave antennas, and for the reconstruction of complex aperture field ... Full text Cite

Modulating and tuning the response of metamaterials at the unit cell level.

Journal Article Optics express · February 2007 We perform a series of simulations and experiments at microwave frequencies where we dynamically alter the magnetic resonance of one individual split ring resonator by photodoping a piece of low-doped semiconductor positioned within the gap of the resonato ... Full text Cite

Microwave focusing and beam collimation using negative index of refraction lenses

Journal Article IET Microwaves, Antennas and Propagation · February 1, 2007 Negative index of refraction materials (NIMs) were first postulated by Veselago in 1968 and have recently been realised using structures formed with rings and wires deposited on printed circuit boards. The proof of the existence of negative index of refrac ... Full text Cite

Microwave holographic imaging technique for tumour detection

Conference IFMBE Proceedings · January 1, 2007 Early, accurate and efficient screening of tumour will go a long way to improve the life expectancy and quality of life. Microwave holographic technique uses nonionising radiation which has the potential to screen patients for tumour at low cost. It offers ... Full text Cite

Microwave holographic imaging of breast cancer

Conference IEEE 2007 International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, MAPE · January 1, 2007 Breast cancer is one of the most common forms of cancer in women. X-ray mammography is the most widely used technique for early detection but has limitations. In this paper, an alternative approach for breast cancer detection using microwave imaging is pre ... Full text Cite

Quantitative investigation of a terahertz artificial magnetic resonance using oblique angle spectroscopy

Journal Article Applied Physics Letters · 2007 The authors present a spectroscopic analysis of a planar split-ring-resonator (SRR) medium at terahertz frequencies, quantitatively characterizing the associated magnetic resonance. Experimental quantification at terahertz and infrared frequencies of metam ... Full text Link to item Cite

Electric-field-coupled metamaterials for microwave beam formation

Journal Article IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · 2007 Microwave propagation through an eleetrie-field-coupled metamaterial lens with a refractive index gradient is experimentally investigated. A gradient in the refractive index of the metamaterial is introduced by continuous tuning of a single parameter in th ... Full text Cite

3D Microwave imaging for medical and security applications

Conference 2006 International RF and Microwave Conference, (RFM) Proceedings · December 1, 2006 The use of microwaves for imaging applications is currently of much research interest particularly in the areas of security imaging and medical imaging. Microwaves have been shown to be able to image objects concealed beneath clothing and recent research w ... Full text Cite

A novel organic fiber for fiber reinforced structural composites

Journal Article 6th Annual SPE Automotive Composites Conference 2006 · December 1, 2006 A novel fiber technology is being developed for the fiber reinforced composites industry. The fiber is a form of poly vinyl alcohol (PVOH). When added to conventional fiber reinforced composite PVOH fiber gives exceptional impact resistance, surface finish ... Cite

Free space microwave focusing by a negative-index gradient lens

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · November 21, 2006 Metamaterial structures designed to have simultaneously negative permittivity and permeability are known as left-handed materials. Their complexity and our understanding of their properties have advanced rapidly to the point where direct applications are n ... Full text Cite

Development and testing of a 2-D transfer CCD

Journal Article IEEE Transactions on Electron Devices · November 1, 2006 This paper describes the development, operation, and characterization of charge-coupled devices (CCDs) that feature an electrode structure that allows the transfer of charge both horizontally and vertically through the image area. Such devices have been te ... Full text Cite

Metamaterial electromagnetic cloak at microwave frequencies.

Journal Article Science (New York, N.Y.) · November 2006 A recently published theory has suggested that a cloak of invisibility is in principle possible, at least over a narrow frequency band. We describe here the first practical realization of such a cloak; in our demonstration, a copper cylinder was "hidden" i ... Full text Cite

EMCCDs for space applications

Conference Proceedings of SPIE - The International Society for Optical Engineering · October 17, 2006 This paper describes a qualification programme for Electron-Multiplication Charge Coupled Devices (EMCCDs) for use in space applications. While the presented results are generally applicable, the programme was carried out in the context of CCD development ... Full text Cite

Preliminary results from herschel-SPIRE flight instrument testing

Conference Proceedings of SPIE - The International Society for Optical Engineering · October 2, 2006 The Spectral and Photometric Imaging REceiver (SPIRE) is one of the three scientific instruments to fly on the European Space Agency's Herschel Space Observatory, and contains a three-band imaging submillimetre photometer and an imaging Fourier transform s ... Full text Cite

A microwave indirect holographic system for security and medical imaging applications

Conference European Space Agency, (Special Publication) ESA SP · October 1, 2006 This work details how an indirect microwave holographic technique originally developed for antenna measurements can be extended to imaging applications. It outlines how complex field patterns can be reconstructed from holographic intensity patterns. It als ... Cite

Imaging dielectric objects using a novel synthetic off-axis holographic technique

Journal Article Microwave and Optical Technology Letters · October 1, 2006 Original results are presented for the imaging of dielectric objects using an indirect planar microwave imaging system that employs an off-axis holographic concept. The ability of this intensity only planar recording technique to recover phase information ... Full text Cite

Calculation of material properties and ray tracing in transformation media.

Journal Article Optics express · October 2006 Complex and interesting electromagnetic behavior can be found in spaces with non-flat topology. When considering the properties of an electromagnetic medium under an arbitrary coordinate transformation an alternative interpretation presents itself. The tra ... Full text Cite

Spatial mapping of the internal and external electromagnetic fields of negative index metamaterials.

Journal Article Optics express · September 2006 We perform an experimental study of the phase and amplitude of microwaves interacting with and scattered by two-dimensional negative index metamaterials. The measurements are performed in a parallel plate waveguide apparatus at X-band frequencies (8-12 GHz ... Full text Cite

Full-wave simulations of electromagnetic cloaking structures.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · September 2006 Pendry et al. have reported electromagnetically anisotropic and inhomogeneous shells that, in theory, completely shield an interior structure of arbitrary size from electromagnetic fields without perturbing the external fields. Neither the coordinate trans ... Full text Cite

Characterization of a planar artificial magnetic metamaterial surface.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · September 2006 We explore the electromagnetic characterization of a planar artificial magnetic metamaterial. Because the composite structure is two- rather than three-dimensional, it does not form a medium with assignable bulk properties, such as the electric permittivit ... Full text Cite

Calculation and measurement of bianisotropy in a split ring resonator metamaterial

Journal Article Journal of Applied Physics · August 11, 2006 A medium that exhibits artificial magnetism can be formed by assembling an array of split ring resonators (SRRs) - planar conducting elements that exhibit a resonant response to electromagnetic radiation. The SRR exhibits a large magnetic dipole moment whe ... Full text Cite

Negative refractive index metamaterials

Journal Article Materials Today · July 1, 2006 Engineered materials composed of designed inclusions can exhibit exotic and unique electromagnetic properties not inherent in the individual constituent components. These artificially structured composites, known as metamaterials, have the potential to fil ... Full text Cite

The quest for the superlens.

Journal Article Scientific American · July 2006 Full text Cite

Controlling electromagnetic fields.

Journal Article Science (New York, N.Y.) · June 2006 Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields-electric displacement field D, magnetic induction field B, and Poynting vector B-are al ... Full text Cite

Free-space microwave focusing by a negative-index gradient lens

Journal Article Applied Physics Letters · March 3, 2006 Metamaterial structures designed to have simultaneously negative permittivity and permeability are known as left-handed materials. Their complexity and our understanding of their properties have advanced rapidly to the point where direct applications are n ... Full text Cite

Experimental investigation of breast tumor imaging using indirect microwave holography

Journal Article Microwave and Optical Technology Letters · March 1, 2006 A novel indirect holographic technique for the early detection of breast cancer, which offers considerable benefits in terms of simplicity and expense, is presented and discussed. It is shown how this approach, usually employed at optical frequencies, can ... Full text Cite

Electric-field-coupled resonators for negative permittivity metamaterials

Journal Article Applied Physics Letters · February 6, 2006 A lithographically patterned inductive-capacitive resonator is described that has a strong electric response. This resonator can be used to construct metamaterials with desired positive or negative permittivity. Such materials provide an alternative to wir ... Full text Cite

Proton irradiation of EMCCDs

Journal Article IEEE Transactions on Electron Devices · February 1, 2006 This paper describes the irradiation of 95 electron multiplication charge coupled devices (EMCCDs) at the Paul Scherrer Institut (PSI) in Switzerland, to investigate the effects of proton irradiation on the operational characteristics of CCDs featuring ele ... Full text Cite

Numerical simulations of long-range plasmons.

Journal Article Optics express · February 2006 We present simulations of plasmonic transmission lines consisting of planar metal strips embedded in isotropic dielectric media, with a particular emphasis on the long-range surface plasmon polariton (SPP) modes that can be supported in such structures. Ou ... Full text Cite

Numerical simulations of plasmonic transmission lines

Journal Article Optics InfoBase Conference Papers · January 1, 2006 We present simulations of plasmonic transmission lines consisting of metal strips embedded in dielectric media. Our numerical method is based on calculating the eigenmodes using a finite-element method as will be illustrated by several examples. © 2005 Opt ... Cite

Early stage breast cancer detection using indirect microwave holography

Conference Proceedings of the 36th European Microwave Conference, EuMC 2006 · January 1, 2006 A novel microwave imaging approach for early stage breast cancer detection is described. The proposed technique involves the use of an Indirect Microwave Holographic technique employing a patented synthetic reference wave. This approach offers benefits in ... Full text Cite

Homogenization of metamaterials by field averaging (invited paper)

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 2006 Over the past several years, metamaterials have been introduced and rapidly been adopted as a means of achieving unique electromagnetic material response. In metamaterials, artificially structured - often periodically positioned - inclusions replace the at ... Full text Cite

Spectroscopy of metamaterials from infrared top optical frequencies

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 2006 We review both the theoretical electromagnetic response and the spectroscopic measurements of metamaterials. To critically examine published results for metamaterial structures operating in the range from terahertz to optical frequencies, we focus on proto ... Full text Cite

Toward artificial magnetism using terahertz split ring resonator metamaterials

Journal Article Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS · January 1, 2006 Split Ring Resonator arrays have been fabricated to demonstrate magnetic resonance in the terahertz regime. Spectroscopic transmission measurements as a function of oblique angle enable quantitative values of the permeability to be calculated © 2006 IEEE. ... Full text Cite

A DoD perspective on left handed negative index materials and potential applications

Journal Article Materials Research Society Symposium Proceedings · January 1, 2006 In the quest for ever smaller, lighter weight, and conformal components and devices for radar and communication applications, researchers in the RF community have increasingly turned to artificially engineered, composite structures (or "metamaterials") in ... Full text Cite

Microwave imaging of concealed metal objects using a novel indirect holographic method

Journal Article Microwave and Optical Technology Letters · December 20, 2005 A novel, inexpensive technique for the detection of concealed metal objects is presented and discussed. It is shown that an indirect holographic method, usually employed at optical frequencies, can he adapted to image objects at microwave frequencies. The ... Full text Cite

Experimental characterization of magnetic surface plasmons on metamaterials with negative permeability

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 13, 2005 We study the surface plasmons (SPs) that exist at the interface between air and a metamaterial constructed of split ring resonators (SRRs). The SRR metamaterial possesses a frequency band in the microwave regime (12.5-14 GHz) over which the permeability is ... Full text Cite

Imaging of dielectric objects from phase patterns reconstructed using indirect holographic intensity patterns

Conference ICEAA 2005 - 9th International Conference on Electromagnetics in Advanced Applications and EESC 2005 - 11th European Electromagnetic Structures Conference · December 1, 2005 This work provides a discussion of a technique developed at Northumbria University that enables full 3D object images to be recorded in a 2D intensity pattern, by utilizing the holographic principle originally developed as an optical technique. ... Cite

Imaging dielectric objects from scalar intensity patterns by means of indirect holography

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · December 1, 2005 An indirect microwave holographic technique for the reconstruction of complex scattered fields and the imaging of objects from a single holographic intensity pattern is described. The holographic intensity pattern is constructed by combining the signal sca ... Full text Cite

Gaia astrometric CCDs and focal plane

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2005 ESA's Gaia astrometry mission is due for launch in 2011. The astrometric instrument focal plane will have an area of up to 0.5m2 and will contain more than 100 CCDs. These will be operated in Time Delay and Integration mode in order to track and observe so ... Full text Cite

MOS CCDs for the Wide Field Imager on the XEUS Spacecraft

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2005 In recent years the XEUS mission concept has evolved and has been the subject of several industrial studies. The mission concept has now matured to the point that it could be proposed for a Phase A study and subsequent flight programme. The key feature of ... Full text Cite

Application of electron multiplying CCD technology in space instrumentation

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2005 Electron multiplying CCD (EMCCD) technology has found important initial applications in low light surveillance and photon starved scientific instrumentation. This paper discusses the attributes of the EMCCD which make it useful for certain space instrument ... Full text Cite

New optics using negative refraction

Journal Article 2005 OSA Topical Meeting on Information Photonics, IP 2005 · December 1, 2005 We summarize the benefits that negative index materials (NIMs), realizable in artificially constructed metamaterials, can have on both geometrical and wave optics. NIMs may lead to novel or improved future optical devices. © Optical Society of America. ... Cite

Fabrication and optical measurements of nanoscale meta-materials: Terahertz and beyond

Journal Article The Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics, 2005. IRMMW-THz 2005 · December 1, 2005 Cite

Simulation and testing of a graded negative index of refraction lens

Journal Article Applied Physics Letters · August 29, 2005 A gradient index (GRIN) lens using a negative index of refraction material (NIM) has been designed and tested. The GRIN lens was fabricated using a NIM slab with a variable index of refraction perpendicular to the propagation direction. Ray tracing calcula ... Full text Cite

Sub-diffraction imaging with compensating bilayers

Journal Article New Journal of Physics · August 8, 2005 We derive a general expression for the material properties of a compensating bilayer, which is a pair of material layers which transfer the field distribution from one side of the bilayer to the other with resolution limited only by the deviation of the ma ... Full text Cite

Negative Index Lenses

Journal Article · August 2, 2005 Full text Cite

Infrared spectroscopy and ellipsometry of magnetic metamaterials

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · July 21, 2005 We present S and P polarized measurements of artificial bianisotropic magnetic metamaterials with resonant behavior at infrared frequencies. These metamaterials consist of an array of micron sized (∼40μm) copper rings fabricated upon a quartz substrate. Si ... Full text Cite

Proton irradiation of e2v technologies L3Vision devices

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · July 11, 2005 This paper describes the proton irradiation and subsequent analysis of 8 e2v technologies CCD65 L3Vision devices with the intention of assessing the suitability of L3Vision technology to applications in space. In particular the use of L3Vision charge coupl ... Full text Cite

Impact of inherent periodic structure on effective medium description of left-handed and related metamaterials

Journal Article Physical Review B - Condensed Matter and Materials Physics · June 15, 2005 We study the frequency dependence of the effective electromagnetic parameters of left-handed and related metamaterials of the split ring resonator and wire type. We show that the reduced translational symmetry (periodic structure) inherent to these metamat ... Full text Cite

Applied physics. How to build a superlens.

Journal Article Science (New York, N.Y.) · April 2005 Full text Cite

Enhanced diffraction by a rectangular grating made of a negative phase-velocity (or negative index) material

Journal Article Physics Letters, Section A: General, Atomic and Solid State Physics · March 28, 2005 The diffraction of electromagnetic plane waves by a rectangular grating formed by discrete steps in the interface of a homogeneous, isotropic, linear, negative phase-velocity (negative index) material with free space is studied using the semi-analytic C me ... Full text Cite

Electromagnetic parameter retrieval from inhomogeneous metamaterials.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · March 2005 We discuss the validity of standard retrieval methods that assign bulk electromagnetic properties, such as the electric permittivity epsilon and the magnetic permeability mu, from calculations of the scattering (S) parameters for finite-thickness samples. ... Full text Cite

Gradient index metamaterials.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · March 2005 Metamaterials--artificially structured materials with tailored electromagnetic response--can be designed to have properties difficult or impossible to achieve with traditional materials fabrication methods. Here we present a structured metamaterial, based ... Full text Cite

New optics using negative refraction

Journal Article Optics InfoBase Conference Papers · January 1, 2005 We summarize the benefits that negative index materials (NIMs), realizable in artificially constructed metamaterials, can have on both geometrical and wave optics. NIMs may lead to novel or improved future optical devices. © Optical Society of America. ... Cite

The effect of the prompt particle environment at L2 on optical CCDs for astronomy and astrophysics

Journal Article Planetary and Space Science · January 1, 2005 The increasing number of probes carrying large focal planes consisting of many charge-coupled devices (CCDs), planned to be sent to the L2 Lagrangian point, 1.5 million kilometres from Earth in the next 15 years, implies that a detailed study of the effect ... Full text Cite

Mechanical design of the NSTX high-k scattering diagnostic

Conference Proceedings - Symposium on Fusion Engineering · January 1, 2005 The NSTX High-k Scattering Diagnostic measures small-scale density fluctuations by the heterodyne detection of waves scattered from a millimeter wave probe beam at 280 GHz and λ=1. 07 mm. To enable this measurement, major alterations were made to the NSTX ... Full text Cite

Superlens breaks optical barrier

Journal Article Physics World · January 1, 2005 A lens developed by physicists that can image nano-scale objects using visible light is discussed. It is found that diffraction restricts the resolution of microscopes and other optical devices to the wavelength of light used. The new superlens can produce ... Full text Cite

First results from Herschel-SPIRE performance tests

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 20, 2004 The Spectral and Photometric Imaging REceiver (SPIRE) is one of the three scientific instruments on the European Space Agency's Herschel mission. At the start of 2004 the Cryogenic Qualification Model (CQM) of SPIRE was tested with the aim of verifying the ... Full text Cite

Integrated sensing networks in composite materials

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 17, 2004 Increasingly, the demand to monitor structures in service is driving technology in new directions. Advances in many areas including novel sensor technologies afford new opportunities in structural health monitoring. We present efforts to develop structural ... Full text Cite

High efficiency class-F Power Amplifier design

Conference IEEE High Frequency Postgraduate Student Colloquium · December 1, 2004 In this paper, a high efficiency, low voltage, class-F Power Amplifier (PA) is described. The effect of different output harmonic terminations on the Power-Added Efficiency (PAE) of the PA has also been analysed. A medium power PHEMT PA operating at 900MHz ... Cite

Imaging concealed objects from scalar microwave holograms

Conference 2004 RF and Microwave Conference, RFM 2004 - Proceedings · December 1, 2004 A new technique for the imaging of concealed objects using indirect holographic imaging principles is outlined. A brief examination of the underlying theory followed by a description of the novel experimental system that has been developed to overcome some ... Cite

Low noise charge injection in the CCD22

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2004 The inclusion of a charge injection structure on a charge coupled device (CCD) allows for the mitigation of charge transfer loss which can be caused by radiation induced charge trapping defects. Any traps present in the pixels of the CCD are filled by the ... Full text Cite

Negative index lens aberrations.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · December 2004 We examine the Seidel aberrations of thin spherical lenses composed of media with refractive index not restricted to be positive. We find that consideration of this expanded parameter space allows for the reduction or elimination of more aberrations than i ... Full text Cite

A high efficiency class-f power amplifier design technique

Journal Article Microwave Journal · November 1, 2004 In this article, a medium power pseudomorphic HEMT device is used in the design of a high efficiency class-F power amplifier (PA) operating at 900 MHz. The purpose of this article is to describe the design procedure of a class-F PA with a very low drain bi ... Cite

Comment I on "Resonant and antiresonant frequency dependence of the effective parameters of metamaterials"

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · October 1, 2004 Full text Cite

Enhanced diffraction from a grating on the surface of a negative-index metamaterial

Journal Article Physical Review Letters · September 24, 2004 The stepping of the refraction interface, due to the finite unit cell size was showed by numerical simulation and by measurements on negative-index metamaterial wedge samples. The surface stepping on the metamaterial sample constitutes a grating, which cou ... Full text Cite

Design of metamaterials with negative refractive index

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · September 13, 2004 Due to the recent experimental validations of left-handed metamaterials, negative refractive index has now become recognized as a new parameter space for the electromagnetic response of materials. Because materials with negative index behave quite differen ... Full text Cite

Random telegraph signals in charge coupled devices

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · September 11, 2004 An investigation of fluctuating pixels resulting from proton irradiation of an E2V Technologies CCD47-20 device is presented. The device structure, experimental set up and irradiation methodology are described, followed by a detailed analysis of radiation ... Full text Cite

Towards a theory of flavor from orbifold GUTs

Journal Article Journal of High Energy Physics · September 1, 2004 We show that the recently constructed 5-dimensional supersymmetric S 1 /(Z2 × Z′2) orbifold GUT models allow an appealing explanation of the observed hierarchical structure of the quark and lepton masses and mixing angles. Flavor hierarchies arise from the ... Full text Cite

Metamaterials and negative refractive index

Journal Article Science · August 6, 2004 Recently, artificially constructed metamaterials have become of considerable interest, because these materials can exhibit electromagnetic characteristics unlike those of any conventional materials. Artificial magnetism and negative refractive index are tw ... Full text Cite

Surface-enhanced Raman scattering from silver-plated porous silicon

Journal Article Journal of Physical Chemistry B · August 5, 2004 Silver micro- and nanocrystallites are prepared on porous Si substrates by immersion plating, and their activity toward SERS (surface-enhanced Raman scattering) is assessed. Scanning electron microscopy reveals a rough silver film containing randomly space ... Full text Cite

Development of the CCDs for ESA's GAIA cornerstone mission

Conference Proceedings of SPIE - The International Society for Optical Engineering · May 3, 2004 The ESA cornerstone mission GAIA will perform astrometric and photometric measurements on one billion objects, and is due for launch in 2010 into L2 orbit. The key astrometric focal plane will comprise over 180 large area CCDs with a focal surface of about ... Full text Cite

CCDs for the Radial Velocity Spectrometer on GAIA

Conference Proceedings of SPIE - The International Society for Optical Engineering · May 3, 2004 The ESA cornerstone mission GAIA will perform astrometric, photometric and spectroscopic measurements and is due for launch in 2010 into L2 orbit. The astrometric telescope system will catalogue the position of over 109 objects down to 20th magnitude and p ... Full text Cite

Proton damage in the E2V swept charge device

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · April 1, 2004 The swept charge device has been developed using CCD technology to perform photon counting X-ray spectroscopy in the 0.5-10keV band as an alternative to silicon PIN and drift diode detectors. The key benefits of the detector are large area, combined with r ... Full text Cite

Angle resolved microwave spectrometer for metamaterial studies

Journal Article Review of Scientific Instruments · April 1, 2004 The angle resolved microwave spectrometer (ARMS) provides highly reproductible automated data acquisition of microwave refraction from positive and negative refracting samples. The flexibility of the instrument allows many types of metamaterial experiments ... Full text Cite

Partial focusing of radiation by a slab of indefinite media

Journal Article Applied Physics Letters · March 29, 2004 The indefinite medium slab for which the permeability component along the z-axis of propagation was negative, while other permeability and permittivity tensors were positive was discussed. It was observed from simulations and transmission experiments on th ... Full text Cite

Terahertz magnetic response from artificial materials.

Journal Article Science (New York, N.Y.) · March 2004 We show that magnetic response at terahertz frequencies can be achieved in a planar structure composed of nonmagnetic conductive resonant elements. The effect is realized over a large bandwidth and can be tuned throughout the terahertz frequency regime by ... Full text Cite

Erratum: A broadband microstrip antenna: SGMEP antenna (Microwave Opt Technol Lett (2003) 39, (175-178))

Journal Article Microwave and Optical Technology Letters · February 20, 2004 Full text Cite

What precision electroweak physics says about the [Formula Presented] little Higgs model

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 2004 We study precision electroweak constraints on the close cousin of the littlest Higgs model, the [Formula Presented] model. We identify a near-oblique limit in which the heavy [Formula Presented] and [Formula Presented] decouple from the light fermions, and ... Full text Cite

Reply to Comments on “Resonant and antiresonant frequency dependence of the effective parameters of metamaterials”

Journal Article Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics · January 1, 2004 We argue, in agreement with our previous work, that periodicity of the metamaterial is responsible for antiresonant behavior of the effective permittivity as well as for the negative sign of the imaginary part of an effective permittivity or permeability. ... Full text Cite

Indirect holographic imaging of antennas using an electronically synthesised "slow-wave"

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · January 1, 2004 The use of indirect holographic techniques, where radiation characteristics and antenna aperture fields can be obtained from simple intensity measurements made in the near field, has traditionally been restricted to the measurement of large antennas with s ... Full text Cite

Negative refraction in indefinite media

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 2004 Initial experiments on wedge samples composed of isotropic metamaterials with simultaneously negative permittivity and permeability have indicated that electromagnetic radiation can be negatively refracted. In more recently reported experiments [Phys. Rev. ... Full text Cite

Design and Measurement of Anisotropic Metamaterials that Exhibit Negative Refraction

Journal Article IEICE Transactions on Electronics · January 1, 2004 Artificial electromagnetic structures have significantly broadened the range of wave propagation phenomena available. In particular, it has been shown that metamaterials can be constructed for which the index-of-refraction is negative over a finite band of ... Cite

Beating the diffraction limit

Journal Article Physics World · January 1, 2004 The subject of negative-index phenomena is drawing significant interest among researchers due to the emergence of a new class of artificially structured materials called metamaterials. Such materials can be engineered so that they have a much wider range o ... Full text Cite

Fabrication and characterization of a negative-refractive-index composite metamaterial

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2004 We have designed, produced, and experimentally characterized 2.7 mm thick composite panels having negative refractive index between 8.4 and 9.2 GHz. The composite metamaterial is fabricated using conventional commercial multilayer circuit-board lithography ... Full text Cite

Reversing light with negative refraction

Journal Article Physics Today · January 1, 2004 The phenomenon of negative refraction is studied. This new field has generated great enthusiasm but also controversy, yet even the controversies have had the positive effect that key concepts have been critically scrutinized in the past 18 months. Many gro ... Full text Cite

Existence and properties of microwave surface plasmons at the interface between a right-handed and a left-handed media

Journal Article IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · January 1, 2004 Surface plasmons (SPs) are interface waves very similar to Zenneck waves but existing only at optical frequencies where metals exhibit a negative permittivity. The availability of novel structured metamaterials with tailorable positive/negative constitutiv ... Full text Cite

3D imaging of antenna fields and metal objects using a new indirect holographic method

Conference ICEAA 2003 - International Conference on Electromagnetics in Advanced Applications · December 1, 2003 This work describes a new technique for producing indirect holographic intensity patterns from which antenna far field radiation patterns can be obtained and images of antenna fields can be reconstructed. It also describes how this technique can be extende ... Cite

Resonant and antiresonant frequency dependence of the effective parameters of metamaterials

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · December 1, 2003 The numerical analysis of the electromagnetic response of two metamaterials which include an array of split ring resonators (SRR) and an array of thin metallic cut wires was presented. It was found that the effective parameters of these systems exhibit res ... Cite

Optical Properties of Coupled Nano Gold Particles

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2003 Nano gold particles interact strongly with visible light to excite the collaborative oscillation of conductive electrons within nano particles resulting in a surface plasmon resonance which makes them useful for various applications including bio-labeling. ... Full text Cite

Spectroscopic studies of individual plasmon resonant nanoparticles

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2003 We present a detailed description of the apparatus and techniques that we have utilized in our experimental study of individual plasmon resonant nanoparticles, along with a brief description of some major results. The apparatus consists of a spectroscopic ... Full text Cite

A broadband microstrip antenna: SGMFP antenna

Journal Article Microwave and Optical Technology Letters · November 5, 2003 A novel structure of broadband microstrip antennas, termed the SGMFP antenna, is proposed. It is consisted of a slot in the ground plane, a microstrip feedline supported on a substrate, a foam layer, and a patch. It can achieve broad bandwidth and high pol ... Full text Cite

The effect of protons on E2V Technologies L3Vision CCDs

Conference Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · November 1, 2003 The effect of different 10 MeV equivalent proton fluences on the performance of E2V Technologies (formerly Marconi applied technologies, formerly EEV) L3Vision Charge Coupled Devices (CCDs) was investigated. The first experimental radiation damage results ... Full text Cite

Microwave indirect holographic imaging using an adaptation of optical techniques

Journal Article IEEE Microwave and Wireless Components Letters · September 1, 2003 Indirect holography provides a quick and inexpensive three-dimensional (3-D) imaging technique at optical frequencies which has not been directly adapted to microwave imaging. This letter describes a technique whereby a radiated offset reference plane wave ... Full text Cite

Interparticle coupling effects on plasmon resonances of nanogold particles

Journal Article Nano Letters · August 1, 2003 The collaborative oscillation of conductive electrons in metal nanoparticles results in a surface plasmon resonance that makes them useful for various applications including biolabeling. We investigate the coupling between pairs of elliptical metal particl ... Full text Cite

Terahertz plasmonic high pass filter

Journal Article Applied Physics Letters · July 7, 2003 Terahertz plasmonic high pass filter was studied. The sharp change of reflection and transmission of electromagnetic waves at plasma frequency made the structure a high pass filter. Fourier transform infrared spectroscopy was used to characterize the refle ... Full text Cite

The impact of low energy proton damage on the operational characteristics of EPIC-MOS CCDs

Journal Article Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms · June 1, 2003 The University of Tübingen 3.5 MeV Van de Graaff accelerator facility was used to investigate the effect of low-energy protons on the performance of the European Photon Imaging Camera, metal-oxide-semiconductor, charge-coupled devices (CCDs). Two CCDs were ... Full text Cite

Spatial filtering using media with indefinite permittivity and permeability tensors

Journal Article Applied Physics Letters · April 7, 2003 The construction of bandpass spatial, low pass and high pass filters was discussed. Bilayers of media with indefinite permittivity and permeability tensors were used for the construction. The filters formed had sharp adjustable roll-offs and could operate ... Full text Cite

The prompt particle background and micrometeoroid environment at L2 and its implications for Eddington

Conference European Space Agency, (Special Publication) ESA SP · April 1, 2003 The Eddington spacecraft will orbit the Sun at the L2 point during its 5 year asteroseismology and planet finding mission. The successful detection of objects of interest and the amount and accuracy of the data that is recorded will depend on the prompt pa ... Cite

Local refractive index dependence of plasmon resonance spectra from individual nanoparticles

Journal Article Nano Letters · April 1, 2003 We present an experimental optical darkfield microscope study of the dependence of the plasmon resonance spectrum of individual silver nanoparticles on the local index of refraction. We systematically characterize the position of the resonance peaks associ ... Full text Cite

Limitations on subdiffraction imaging with a negative refractive index slab

Journal Article Applied Physics Letters · March 10, 2003 Limitations on subdiffraction imaging with a negative refractive index slab was studied. The planar geometry allowed a straight forward analysis to be implemented. The fields from an arbitray electromagnetic source were expanded in a Fourier series over ho ... Full text Cite

Surface plasmon coupling between two nano Au particles

Conference Proceedings of the IEEE Conference on Nanotechnology · January 1, 2003 Nano metal particles which interact strongly with visible light make themselves useful for molecular detection and biosensing. To facilitate the useful application for these nano particles, it is important to design and fabricate the particles at a desired ... Full text Cite

Integrated sensing in structural composites

Conference Structural Health Monitoring 2003: From Diagnostics and Prognostics to Structural Health Management - Proceedings of the 4th International Workshop on Structural Health Monitoring, IWSHM 2003 · January 1, 2003 Increasing demand for monitoring of in-service structures is driving technology in new directions. Advances in many related technologies, including novel sensor design and implementation, have created new opportunities in structural health monitoring. We p ... Cite

Resonant and antiresonant frequency dependence of the effective parameters of metamaterials

Journal Article Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics · January 1, 2003 We present a numerical study of the electromagnetic response of the metamaterial elements that are used to construct materials with negative refractive index. For an array of split ring resonators (SRR) we find that the resonant behavior of the effective m ... Full text Cite

Comment on “Wave Refraction in Negative-Index Media: Always Positive and Very Inhomogeneous

Journal Article Physical Review Letters · January 1, 2003 A Comment on the Letter by P.M. Valanju, R.M. Walser, andA.P. Valanju, Phys. Rev. Lett. 88, 187401 (2002). The authors of the Letter offer a Reply. © 2003 The American Physical Society. ... Full text Cite

3D imaging of antenna fields from electronically synthesised scalar intensity patterns

Conference 2003 Asia-Pacific Conference on Applied Electromagnetics, APACE 2003 - Proceedings · January 1, 2003 This work describes a new technique for the determination of antenna far field radiation patterns and the imaging of antenna fields from holographic intensity patterns. These intensity patterns are obtained by combining the sampled antenna near field with ... Full text Cite

A novel technique for the determination of the radiation patterns of medium gain antennas from scalar intensity measurements

Conference ISAPE 2003 - 2003 6th International Symposium on Antennas, Propagation and EM Theory, Proceedings · January 1, 2003 Holographic techniques have proved useful -for the determination of antenna radiation patterns and imaging antenna fields. Traditionally this has been achieved mainly by the direct measurement of complex near fields of the antenna over a measurement plane ... Full text Cite

‘Voyager’: An educational card game

Journal Article Physics Education · January 1, 2003 �‘Voyager’ is an educational card game involving scientific satellites, developed for use in schools with children aged 9 to 13 years. The idea of the game is to improve pupils’ knowledge about the large number of scientific satellites there are in space i ... Full text Cite

The reality of negative refraction

Journal Article Physics World · January 1, 2003 Recent experiments that demonstrated the negative refraction of light were presented. The refraction at the interface between a positive-index material and a negative index material teared the wave apart, leaving no single negatively refracted wave. The re ... Full text Cite

Electromagnetic Wave Propagation in Media with Indefinite Permittivity and Permeability Tensors

Journal Article Physical Review Letters · January 1, 2003 We study the behavior of wave propagation in materials for which not all of the principal elements of the permeability and permittivity tensors have the same sign. We find that a wide variety of effects can be realized in such media, including negative ref ... Full text Cite

Numerical study of electromagnetic waves interacting with negative index materials

Journal Article Optics Express · January 1, 2003 We study numerically the electromagnetic scattering properties of structures with negative indices of refraction. To perform this analysis, we utilize a commercial finite-element based electromagnetic solver (HFSS, Ansoft), in which a negative index materi ... Full text Cite

Spectrum of TeV particles in warped supersymmetric grand unification

Journal Article Physical Review D · January 1, 2003 In warped supersymmetric grand unification, XY gauge particles appear near the TeV scale along with Kaluza-Klein towers of the standard model gauge fields. In spite of this exotic low-energy physics, the successful gauge coupling unification prediction of ... Full text Cite

Warped supersymmetric grand unification

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 2003 We construct a realistic theory of grand unification in [Formula Presented] truncated by branes, in which the unified gauge symmetry is broken by boundary conditions and the electroweak scale is generated by the AdS warp factor. We show that the theory pre ... Full text Cite

Artificial plasmonic metamaterial fabricated by micro-stereolithography

Journal Article American Society of Mechanical Engineers, Micro-Electromechanical Systems Division Publication (MEMS) · January 1, 2003 Micro-structured materials, which contain engineered sub-wavelength components, can be designed to have positive or negative ε and μ at desired frequency. In this paper, we demonstrate a high pass Terahertz (THz) filter which utilizes the lowered plasma fr ... Full text Cite

Inelastic dark matter at DAMA, CDMS and future experiments

Journal Article Nuclear Physics B - Proceedings Supplements · January 1, 2003 The DAMA annual modulation signature, interpreted as evidence for a spin-independent WIMP coupling, seems in conflict with null results from CDMS. However, in models of "inelastic dark matter", the experiments are compatible. Inelastic dark matter can aris ... Full text Cite

The effect of low energy protons on the operational characteristics of EPIC-MOS CCDs

Conference Proceedings of the European Conference on Radiation and its Effects on Components and Systems, RADECS · December 1, 2002 The University of Tubingen 3.5 MeV Van de Graaf accelerator facility was used to investigate the effect of low energy protons on the performance of the European Photon Imaging Camera (EPIC), metal-oxide semiconductor (MOS), charge coupled devices (CCDs). T ... Cite

Proton induced leakage current in CCDs

Conference Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2002 The effect of different proton fluences on the performance of two E2V Technologies (formerly Marconi Applied Technologies, formerly EEV) CCD47-20 devices was investigated with particular emphasis given to the analysis of 'Random telegraph signal' (RTS) gen ... Full text Cite

Metal nanoparticles for biodetection

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 1, 2002 The large scattering cross section of plasmon resonant gold and silver nanoparticles functionalized with the appropriate ligand allows for sensitive and specific detection of nucleic acids and proteins. By varying the size, shape, and material morphology p ... Full text Cite

SO(10) unified theories in six dimensions

Journal Article Physical Review D · December 1, 2002 We construct supersymmetric models of SO(10) unification in which the gauge symmetry is broken by orbifold compactification. We find that using boundary conditions to break the gauge symmetry down to SU(3) C⊗ SU(2) L ⊗U(1) Y⊗U(1) X without leaving unwanted ... Full text Cite

Negative refraction of modulated electromagnetic waves

Journal Article Applied Physics Letters · October 7, 2002 We show that a modulated Gaussian beam undergoes negative refraction at the interface between a positive and negative refractive index material. While the refraction of the beam is clearly negative, the modulation interference fronts are not normal to the ... Full text Cite

Gauge-higgs unification in higher dimensions

Journal Article Nuclear Physics B · September 9, 2002 The electroweak Higgs doublets are identified as components of a vector multiplet in a higher-dimensional supersymmetric field theory. We construct a minimal model in 6D where the electroweak SU (2) ⊗ U (1) gauge group is extended to SU(3), and unified 6D ... Full text Cite

The asymmetric lossy near-perfect lens

Journal Article Journal of Modern Optics · August 15, 2002 We extend the ideas of the perfect lens recently proposed [J.B. Pendry, Phys. Rev. Lett. 85, 3966 (2000)] to an alternative structure. We show that a slab of a medium with negative refractive index bounded by media of different positive refractive index al ... Full text Cite

An indirect holographic method for determining antenna radiation patterns and imaging antenna fields

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · August 5, 2002 This work describes a new technique for the determination of antenna radiation patterns and the imaging of antenna aperture fields. It uses an indirect holographic method to record simple intensity patterns formed by a combination of antenna near field sig ... Cite

Single crystal silver nanowires prepared by the metal amplification method

Journal Article Journal of Applied Physics · June 1, 2002 We present a method of fabricating single crystal silver nanowires based on the electroless deposition of silver into the pores of the polycarbonate membranes by the metal amplification process. A gold film on one side of the nanoporous membrane is used as ... Full text Cite

Determination of effective permittivity and permeability of metamaterials from reflection and transmission coefficients

Journal Article Physical Review B - Condensed Matter and Materials Physics · May 15, 2002 We analyze the reflection and transmission coefficients calculated from transfer matrix simulations on finite lengths of electromagnetic metamaterials, to determine the effective permittivity (ε) and permeability (μ). We perform this analysis on structures ... Cite

Composite Plasmon Resonant Nanowires

Journal Article Nano Letters · May 1, 2002 We present an experimental study of the polarization-dependent scattering of light from homogeneous and multisegment silver, gold, and nickel nanowires. The metallic nanowires are prepared within a polycarbonate membrane template by a combination of electr ... Full text Cite

The effect of proton damage on the X-ray spectral response of MOS CCDs for the Swift X-ray telescope

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · April 21, 2002 The effect of non-ionising energy loss of protons in charge-coupled devices is to displace silicon atoms and any dopant materials present from their lattice positions to form lattice defects which in turn can trap electrons (IEEE Trans. Nucl. Sci. NS-40 (1 ... Full text Cite

Shape effects in plasmon resonance of individual colloidal silver nanoparticles

Journal Article Journal of Chemical Physics · April 15, 2002 The effect of shape of individual silver colloidal nanoparticle on surface plasmon resonance was investigated by an optical detection technique combined with high resolution transmission electron microscopy (TEM). The geometrical shape of nanoparticle had ... Full text Cite

Fabrication and characterization of THz plasmonic filter

Conference Proceedings of the IEEE Conference on Nanotechnology · January 1, 2002 Terahertz imaging systems have applications for explosives detection, aircraft guidance and landing in zero-visibility weather condition, as well as terrestrial and astronomical remote sensing. These critical applications need a variety of optical elements ... Full text Cite

Determination of effective permittivity and permeability of metamaterials from reflection and transmission coefficients

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 We analyze the reflection and transmission coefficients calculated from transfer matrix simulations on finite lengths of electromagnetic metamaterials, to determine the effective permittivity (ε) and permeability (µ). We perform this analysis on structures ... Full text Cite

Little Higgs bosons from an antisymmetric condensate

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 2002 We construct an (Formula presented) non-linear sigma model in which the Higgs bosons arise as pseudo Goldstone bosons. There are two Higgs doublets whose masses have no one-loop quadratic sensitivity to the cutoff of the effective theory, which can be at a ... Full text Cite

Localized fermions and anomaly inflow via deconstruction

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 2002 We study fermion localization in gauge theory space. We consider four-dimensional product gauge groups in which light chiral fermions transform under different gauge factors of the product group. This construction provides a suppression of higher dimension ... Full text Cite

Plasmon resonances of silver nanowires with a nonregular cross section

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 15, 2001 We investigate numerically the spectrum of plasmon resonances for metallic nanowires with a nonregular Z, cross section, in the 20-50 nm range. We first consider the resonance spectra corresponding to nanowires whose cross sections form different simplexes ... Full text Cite

Small neutrino masses from supersymmetry breaking

Journal Article Physical Review D · December 1, 2001 An alternative to the conventional seesaw mechanism is proposed to explain the origin of small neutrino masses in supersymmetric theories. The masses and couplings of the right-handed neutrino field are suppressed by supersymmetry breaking, in a way simila ... Cite

Ab initio numerical simulation of left-handed metamaterials: Comparison of calculations and experiments

Journal Article Journal of Applied Physics · November 15, 2001 Using numerical simulation techniques, the transmission and reflection coefficients, or S parameters, for left-handed metamaterials are calculated. Metamaterials consist of a lattice of conducting, nonmagnetic elements that can be described by an effective ... Full text Cite

GUT breaking on the brane

Journal Article Nuclear Physics B · October 8, 2001 We present a five-dimensional supersymmetric SU(5) theory in which the gauge symmetry is broken maximally (i.e., at the 5D Planck scale M*) on the same 4D brane where chiral matter is localized. Masses of the lightest Kaluza-Klein modes for the colored Hig ... Full text Cite

Finite radiative electroweak symmetry breaking from the bulk

Journal Article Nuclear Physics B · July 2, 2001 A new physical origin for electroweak symmetry breaking is proposed, involving compact spatial dimensions of scale 1/R≈1 TeV. The higher-dimensional theory is supersymmetric, and hence requires the top-quark Yukawa coupling to be localized on some "Yukawa ... Full text Cite

Dramatic localized electromagnetic enhancement in plasmon resonant nanowires

Journal Article Chemical Physics Letters · June 15, 2001 We investigate numerically the plasmon resonances of 10-50 nm nanowires with a non-elliptical section. Such wires have a much more complex behavior than elliptical wires and their resonances span a larger frequency range. The field distribution at the surf ... Full text Cite

A study of molybdenum influxes and transport in alcator C-Mod

Journal Article Nuclear Fusion · May 1, 2001 A characterization is presented of Mo sources ΓMo, core Mo content NMo and their dependences on the Alcator C-Mod operational regimes. The primary impurity source locations are the divertor, the inner wall and the ICRF antenna limiters. Boronization is use ... Full text Cite

Experimental verification of a negative index of refraction.

Journal Article Science (New York, N.Y.) · April 2001 We present experimental scattering data at microwave frequencies on a structured metamaterial that exhibits a frequency band where the effective index of refraction (n) is negative. The material consists of a two-dimensional array of repeated unit cells of ... Full text Cite

Non-regularly shaped plasmon resonant nanoparticle as localized light source for near-field microscopy.

Journal Article Journal of microscopy · April 2001 We study numerically two-dimensional nanoparticles with a non-regular shape and demonstrate that these particles can support many more plasmon resonances than a particle with a regular shape (e.g. an ellipse). The electric field distributions associated wi ... Full text Cite

Microwave transmission through a two-dimensional, isotropic, left-handed metamaterial

Journal Article Applied Physics Letters · January 22, 2001 We present experimental data, numerical simulations, and analytical transfer-matrix calculations for a two-dimensionally isotropic, left-handed metamaterial (LHM) at X-band microwave frequencies. A LHM is one that has a frequency band with simultaneously n ... Full text Cite

Molybdenum sources and transport in Alcator C-Mod

Journal Article Journal of Nuclear Materials · January 1, 2001 We present a characterization of molybdenum sources, ΓMo, core Mo content, NMo, and their dependencies on Alcator C-Mod operational regimes. This includes sources from the divertor, the inner wall and the ICRF antenna limiters. We also present information ... Full text Cite

Measurements of the branching fractions of exclusive charmless B meson decays with η′ or ω mesons

Journal Article Physical Review Letters · 2001 An overview is given on the results of searches for B decays to the charmless two-body final states B +→wπ +, B +→wK +, B +→η'π ... Cite

Measurement of branching fractions and search for CP-violating charge asymmetries in charmless two-body B decays into pions and kaons

Journal Article Physical Review Letters · 2001 Branching ratios were measured for the rate charmless decays B 0→π +π -, B 0→K +π -, B + ... Cite

Measurement of the decays B → φK and B → φK

Journal Article Physical Review Letters · 2001 An attempt was made to observe B decays to φK +, φK 0, φK *+, and φK *0 with significances, including systematic uncertainties, of greater than four standard de ... Cite

Inelastic dark matter

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 2001 Many observations suggest that much of the matter of the universe is nonbaryonic. Recently, the DAMA NaI dark matter direct detection experiment reported an annual modulation in their event rate consistent with a WIMP relic. However, the Cryogenic Dark Mat ... Full text Cite

Exponentially small supersymmetry breaking from extra dimensions

Journal Article Physical Review D · January 1, 2001 The supersymmetric "shining" of free massive chiral superficiels in extra dimensions from a distant source brane can trigger exponentially small supersymmetry breaking on our brane of order e~27rR, where R is the radius of the extra dimensions. This supers ... Full text Cite

Field polarization and polarization charge distributions in plasmon resonant nanoparticles

Journal Article New Journal of Physics · November 3, 2000 We study the plasmon resonances for small two-dimensional silver particles (nanowires) with elliptical or triangular shapes in the 20 nm size range. While the elliptical particle has only two resonances, a well known fact, we demonstrate that the triangula ... Full text Cite

Direct calculation of permeability and permittivity for a left-handed metamaterial

Journal Article Applied Physics Letters · October 2, 2000 Recently, an electromagnetic metamaterial was fabricated and demonstrated to exhibit a "left-handed" (LH) propagation band at microwave frequencies. A LH metamaterial is one characterized by material constants - the permeability and permittivity - which ar ... Full text Cite

Negative refractive index in left-handed materials

Journal Article Physical Review Letters · October 2, 2000 The presence of negative refractive index in steady-state problems was explored. It was observed that this index leads to unusual and unexplored phenomena in wave propagation. A formalism was derived that can be applied to time dependent currents and pulse ... Full text Cite

Composite medium with simultaneously negative permeability and permittivity

Journal Article Physical review letters · May 2000 We demonstrate a composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with simultaneously negative values of effective permeab ... Full text Cite

Single-target molecule detection with nonbleaching multicolor optical immunolabels.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · February 2000 We introduce and demonstrate the use of colloidal silver plasmon-resonant particles (PRPs) as optical reporters in typical biological assays. PRPs are ultrabright, nanosized optical scatterers, which scatter light elastically and can be prepared with a sca ... Full text Cite

Solving the hierarchy problem with exponentially large dimensions

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 2000 In theories with (sets of) two large extra dimensions and supersymmetry in the bulk, the presence of non-supersymmetric brane defects naturally induces a logarithmic potential for the volume of the transverse dimensions. Since the logarithm of the volume r ... Full text Cite

Spectral response of plasmon resonant nanoparticles with a non-regular shape

Journal Article Optics Express · January 1, 2000 We study the plasmon resonances of 10-100(nm) two-dimensional metal particles with a non-regular shape. Movies illustrate the spectral response of such particles in the optical range. Contrary to particles with a simple shape (cylinder, ellipse) non-regula ... Full text Cite

Negative permeability from split ring resonator arrays

Journal Article Conference on Lasers and Electro-Optics Europe - Technical Digest · January 1, 2000 A single split ring resonator (SRR) was fabricated lithographically and its accompanying resonance curve is shown to determine if periodic arrays of SRRs can have a resonantly enhanced effective permeability displaying frequency regions with large positive ... Cite

Photonic Band Gap accelerator cavity design at 90 GHz

Journal Article Proceedings of the IEEE Particle Accelerator Conference · December 1, 1999 In previous work we have proposed utilizing Photonic Band Gap (PBG) structures as a new class of high-energy, high-intensity accelerator cavities. We have completed extensive MAFIA numerical calculations of multicell PBG structures, with each cell consisti ... Cite

Loop-wire medium for investigating plasmons at microwave frequencies

Journal Article Applied Physics Letters · September 6, 1999 A localized surface plasmon resonance is demonstrated at microwave frequencies. The plasmon structure is based on the assumption that the effective dielectric constant of the loop wire is due to the self-inductance of the constituent wire. The plasmon stru ... Full text Cite

Nanoparticle based biological assays

Journal Article Journal of Clinical Ligand Assay · June 1, 1999 An introduction to the utilization of plasmon resonant particles as optical labels for diverse biological applications is presented. Plasmon resonant particles (PRP(TM)) (Seashell Technology LLC, La Jolla, CA) are sub- micron (40-100 nanometer), ultra-brig ... Cite

Leading order textures for lepton mass matrices

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · June 1, 1999 In theories with three light neutrinos, certain simplicity assumptions allow the construction of a complete list of leading order lepton mass matrices. These matrices are consistent with mτ≠0,Δm122≪Δm232,θ23∼O(1) and θ13=0, as suggested by measurements of ... Cite

Leading order textures for lepton mass matrices

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · May 10, 1999 In theories with three light neutrinos, certain simplicity assumptions allow the construction of a complete list of leading order lepton mass matrices. These matrices are consistent with (Formula presented) and (Formula presented) as suggested by measureme ... Full text Cite

Generalized Field Propagator for Arbitrary Finite-Size Photonic Band Gap Structures

Journal Article Physical Review Letters · January 11, 1999 We investigate the properties of photonic hand gap structures of finite size and arbitrary geometry using the density of states deduced from scattering calculations. We first demonstrate this procedure on a finite 2D array of cylinders and then study at op ... Full text Cite

Actuator-based vibration control using position feedback

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 1999 A control strategy based on the relative position of the armature and body, and an actuator which has the necessary features to take advantage of this approach, is developed. This strategy provides a modular approach to vibration isolation because it acts ... Cite

Cosmological constraints on theories with large extra dimensions

Journal Article Physical Review D - Particles, Fields, Gravitation and Cosmology · January 1, 1999 In theories with large extra dimensions, constraints from cosmology lead to nontrivial lower bounds on the gravitational scale M, corresponding to upper bounds on the radii of the compact extra dimensions. These constraints are especially relevant to the c ... Full text Cite

Oscillations of solar and atmospheric neutrinos

Journal Article Journal of High Energy Physics · January 1, 1998 Motivated by recent results from SuperKamiokande, we study both solar and atmospheric neutrino fluxes in the context of oscillations of the three known neutrinos. We aim at a global view which identifies the various possibilities, rather than attempting th ... Full text Cite

Improved form of backfire bifilar helix conical beam antenna

Journal Article Microwave and Optical Technology Letters · April 5, 1997 The nonresonant-length backfire bifilar helix is often used as a vehicle satcom antenna, as it has a circularly polarized conical beam with azimuthal symmetry. Some antenna configurations, however, exhibit poor back-lobe levels. It is shown that radiation ... Full text Cite

Low cost tyre monitoring system using electronic article surveillance techniques

Conference IEE Colloquium (Digest) · January 1, 1997 A low cost method for tire monitoring is designed using a passive LC circuit tag is used for contactless sensing. Circuit response to bursts of radio frequency pulses is made to vary with changes in tire pressure. Separate transmit and receive antennas are ... Cite

Thermal expansion of an E-glass/vinyl ester composite from 4 to 293 K

Journal Article International Journal of Thermophysics · January 1, 1997 We have measured the thermal expansion of the three principal orthogonal directions of an E-glass/vinyl ester structural composite from liquid helium temperature, 4.2 K, to room temperature, 293 K. The linear thermal expansion at 4.2 K ranged from -0.23 to ... Full text Cite

Thermal conductivity of fibrous glass board by guarded hot plates and heat flow meters: An international round-robin

Journal Article International Journal of Thermophysics · January 1, 1997 In the early 1980s, an international round-robin was held in which the apparent thermal conductivity of specimens of fibrous glass insulation board was measured by users of guarded hot plates (GHPs) and heat-flow meters (HFMs). The round-robin was performe ... Full text Cite

Analytical formulas for the unshielded magnetoresistive head

Journal Article IEEE Transactions on Magnetics · December 1, 1996 The magnetostatic and frequency response characteristics of the unshielded magnetoresistive (UMR) head have been previously calculated by means of a numerical simulation which ultilized the principle of reciprocity to reduce the computational task of solvi ... Full text Cite

Analytic and quasi-analytic formulae for MR heads

Journal Article IEEE Transactions on Magnetics · December 1, 1996 We present analytic procedures for calculating the magnetostatic and response functions of magnetoresistive (MR) recording heads. To apply these methods we make several simplifying approximations, which have been found to be valid for typical recording hea ... Full text Cite

Compact anechoic chamber and antenna measurement system for microwave teaching and research applications

Journal Article Microwave and Optical Technology Letters · June 20, 1996 The design of a small, low-cost anechoic chamber well suited to the teaching of antenna theory and measurement techniques is described. The chamber design allows for dismantling, relocation, and reassembly when required. Its performance in the range 18-30 ... Full text Cite

Experimental and theoretical study of dipole emission in the two-dimensional photonic band structure of the square lattice with dielectric cylinders

Journal Article Journal of Applied Physics · January 15, 1996 Dipole radiation in a two-dimensional periodic dielectric structure is studied both theoretically and experimentally in this article. For the two-dimensional square lattice structure with dielectric cylinders, the emission power of an electric dipole in th ... Full text Cite

Performance of a novel dual-band horn antenna @ 20/30GHz

Conference 1996 26th European Microwave Conference, EuMC 1996 · January 1, 1996 The design for a narrow angle feed horn radiating low levels of cross polarisation in two widely separated frequency bands is presented. The horn uses corrugations to control the cross polarisation in the lower frequency band and a synthesised aperture dis ... Full text Cite

Wide flare-angle horn antenna with means for radiating low levels of crosspolarisation in two widely separated frequency bands

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · January 1, 1996 Preliminary results for a horn antenna with good crosspolar performance in two discrete frequency bands in addition to desirable VSWR characteristics are presented. The horn combines two different design concepts. It uses corrugations to control the crossp ... Cite

New type of waveguide structures with photonic band structures

Journal Article IEEE MTT-S International Microwave Symposium Digest · January 1, 1996 We study a new type of waveguide structures - two-dimensional photonic crystals sandwiched between two metal conductors. In the structures, not only the electromagnetic propagation, but also the radiation spectra can be controlled. Radiation from microwave ... Cite

High duty factor electron linac for FEL

Journal Article Proceedings of the IEEE Particle Accelerator Conference · December 1, 1995 An 18-MeV, 433-MHz linac capable of operating at 25% RF duty factor (DF) is being commissioned for FEL applications. Comprising a two-cell RF photocathode injector followed by four new multicell cavities, the linac is an extension of the photoinjector whic ... Cite

User-configurable MAGIC for electromagnetic PIC calculations

Journal Article Computer Physics Communications · May 2, 1995 MAGIC is a user-configurable code that solves Maxwell's equations together with Lorentz particle motion. A variety of 2D, finite-difference electromagnetic algorithms and 3D particle-in-cell algorithms may be combined in problem-specific ways to provide fa ... Full text Cite

Design, construction and performance of a small, low cost anechoic measuring system for research applications

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · January 1, 1995 A low cost anechoic measuring system has been designed, constructed and evaluated. It consists of a small anechoic chamber, designed specifically for measurements of high performance feed horns within the range 18-30GHz, and a simple antenna positioner. Th ... Cite

Enhanced teaching of antenna theory and measurement techniques using a low cost anechoic measuring system

Conference 1995 25th European Microwave Conference · January 1, 1995 A low cost anechoic chamber and simple antenna positioner have been constructed. They have been incorporated into a fully automated antenna pattern measuring system which takes advantage of the department's existing network analyser as both the source and ... Full text Cite

Modelling the interaction of multiple small harmonic current sources in an isolated power distribution system

Journal Article Can. J. Electr. Comput. Eng. (Canada) · 1995 Given the growing number of interactive nonlinear loads in power distribution systems, some techniques to monitor the spread of harmonics through the power system need to be developed. This paper examines the nature of harmonics in a naval power distributi ... Cite

A circuit-switched shared-memory multiprocessor

Journal Article Int. J. Mini Microcomput. (USA) · 1995 A circuit-switched shared-memory multiprocessor based on the 2D spanning bus hypercube is described. This design eliminates most of the processing overhead attributed to message passing systems. Circuit switching allows the sender to transfer directly into ... Cite

Experimental and theoretical results for a two-dimensional metal photonic band-gap cavity

Journal Article Applied Physics Letters · December 1, 1994 We demonstrate, by both microwave experiments and numerical simulation, that a two-dimensional lattice of metal cylinders can form a complete photonic band-gap (PBG) structure. The band structure exhibits a single broad PBG extending from zero frequency to ... Full text Cite

Overview of the beam emission spectroscopy diagnostic system on the National Spherical Torus Experiment

Journal Article IEEE Transactions on Magnetics · January 1, 1994 A beam emission spectroscopy (BES) system has been installed on the National Spherical Torus Experiment (NSTX) to study ion gyroscale ?uctuations. The BES system measures Dαemission from a deuterium neutral heating beam. The system includes two optical vie ... Full text Cite

Defect studies in a two-dimensional periodic photonic lattice

Journal Article J. Mod. Opt. (UK) · 1994 Structures arranged so as to exhibit a complete photonic bandgap (PGB) have been proposed for a variety of technological applications. McCall et al. have reported an experimental and numerical investigation of microwave propagation in a two-dimensional arr ... Cite

Photonic band gap resonators for high energy accelerators

Journal Article Proceedings of the IEEE Particle Accelerator Conference · December 1, 1993 We have proposed that a new type of microwave resonator, based on Photonic Band Gap (PBG) structures, may be particularly useful for high energy accelerators. We provide an explanation of the PBG concept and present data which illustrate some of the specia ... Cite

Photonic band structure and defects in one and two dimensions

Journal Article Journal of the Optical Society of America B: Optical Physics · January 1, 1993 We present an experimental and numerical study of electromagnetic wave propagation in one-dimensional (D) and two-dimensional (2D) systems composed of periodic arrays of dielectric scatterers. We demonstrate that there are regions of frequency for which th ... Full text Cite

Effects of load impedance os the dimensions and beamwidth of a dual feed nearly square patch antenna for circular polarisations

Conference IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) · January 1, 1992 Full text Cite

Analysis Of A Dual Magnetoresistive Head

Journal Article IEEE Transactions on Magnetics · January 1, 1992 A recently proposed dual magnetoresistive (DMR) reproduce head, consisting of two identical, adjacent MR stripes separated by a nonmagnetic spacer and connected electrically in parallel, was shown to have potential in very high density magnetic recording a ... Full text Cite

Dual circular polarised microstrip antenna design for a passive microwave transponder

Conference IEE Conference Publication · January 1, 1991 This work has extended the use of a simple cavity model to the case of a dual feed nearly square antenna for circular polarisation. The addition of the second feed is found to alter the conditions required for the generation of circular polarisation and re ... Cite

Microwave propagation in two-dimensional dielectric lattices

Journal Article Physical Review Letters · January 1, 1991 We have calculated and measured the properties of X-band microwaves propagating in a 2D array of low-loss high-dielectric-constant cylinders. Transmission bands and photonic band gaps are conclusively identified in excellent agreement with the theoretical ... Full text Cite

Dual polarized microstrip antenna design for a polarization shift keying microwave transponder

Conference Conference Proceedings - European Microwave Conference · December 1, 1989 This work describes a novel method of data transmission by means of polarization shift keying. It analyzes the system performance in terms of S/N ratio and defines the required antenna cross polarization performance to achieve an acceptable S/N ratio. A th ... Cite

Cryogenic infrared radiance instrumentation for shuttle (Cirris)

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · April 3, 1981 In recent years, the Air Force Geophysics Laboratory has flown several rocketborne experiments with cryogenic interferometers to measure natural and induced infrared atmospheric emissions. AFGL is currently developing two separate shuttle payloads based on ... Full text Cite