Scholars@Duke
Michael E. Gehm

Michael E. Gehm

Professor of Electrical and Computer Engineering
Pierre R. Lamond Department of Electrical and Computer Engineering
michael.gehm@duke.edu
Box 90291, Durham, NC 27708
3463 CIEMAS, Fitzpatrick Center, Durham, NC 27708

Scholarly Works - Conferences

Further Development of Asymmetric Illumination X-Ray Differential Phase Contrast Imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2024 X-ray phase contrast imaging, which measures the change in phase through an object rather than change in attenuation, excels at distinguishing between similarly attenuating materials when compared to conventional transmission imaging. Most methods of phase ... Full text Cite

Spectrally Responsive Edge Illumination X-ray Phase Contrast Imaging (XPCI)

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2024 As opposed to transmission imaging, X-ray Phase Contrast Imaging (XPCI) produces images with higher contrast and allows us to distinguish between materials that are weakly attenuating or between materials that possess similar attenuation values. Edge Illum ... Full text Cite

Design and solution-based testing of a synthetic aerosol particle with asymmetric scattering behavior

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2024 We have modeled, synthesized, and performed preliminary testing of a synthetic aerosol particle with the intent to affect an asymmetric (“one-way”) vision environment when deployed as an airborne plume and aligned in real time via an applied acoustic field ... Full text Cite

Performance of a high-throughput full-tunnel XRD checked baggage scanning system

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2023 X-ray diffraction imaging (XRDI) offers the potential for reduced false alarm rates, increased throughputs, and more sensitive explosives detection performance in aviation security applications. The deployment of computed tomography (CT) systems across car ... Full text Cite

Simulation and information-theoretic analysis of a hybrid CT+XRD imaging system

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2023 Simulation is a valuable tool for designing and evaluating the performance of x-ray imaging systems. In previous work,1, 2 a hybrid computed tomography(CT) and x-ray diffraction(XRD) imaging system was developed for improved identification of th ... Full text Cite

Spectrally Responsive Edge Illumination X-ray Phase Contrast Imaging (XPCI)

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2023 X-ray Phase Contrast Imaging (XPCI) is an imaging method used to retrieve phase information from an object, thereby revealing more object characteristics, such as refractive index and thickness. Edge Illumination (EI) is a non-interferometric type of XPCI ... Full text Cite

Asymmetric Illumination X-Ray Differential Phase Contrast Imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2023 X-ray phase contrast imaging has the potential to improve image contrast and better differentiate between weakly attenuating materials. Current implementations, however, focus on small biological samples and coherent sources. Here we propose asymmetric ill ... Full text Cite

Imaging asymmetry in the presence of a bright interferent

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2023 Previously, Alyones et. al. (Appl Opt. 54 (2015)),1 showed that a pair of aerosol plumes — one purely scattering, the other purely absorbing—in the presence of a bright interferent, had the interesting property that the imaging contrast ratios t ... Full text Cite

Towards creation of an asymmetric vision environment

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2023 Airborne scattering media, such as fog, obstructs imaging by destroying the one-to-one object to image mapping relationship through a multiple scattering process. Existing research in this area is predicated on developing methods to image despite this scat ... Full text Cite

Characterization of photon counting detectors for x-ray diffraction (XRD) applications

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2022 Photon counting detectors with energy resolving capabilities have the potential to improve computed tomography (CT) imaging and x-ray diffraction (XRD) systems. In order to better understand the use of these detectors in the CT and XRD application spaces, ... Full text Cite

Spectrally responsive edge-illumination (SREI) x-ray phase contrast imaging (XPCI)

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2022 X-ray Phase Contrast Imaging (XPCI) is an imaging method that can provide quantitative information about the change in phase of X-ray wavefronts as they pass through an object. XPCI can image objects that cannot be easily seen in conventional absorption im ... Full text Cite

Design and analysis of a hybrid X-ray transmission and diffraction system

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2021 Aviation security, mail inspection, medical diagnostics and many other industries all face the same challenge: to accurately identify the presence of a target material concealed within a cluttered surrounding environment. X-ray systems that combine transmi ... Full text Cite

Task-specific information in X-ray diffraction and transmission modalities: A comparative analysis

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2020 We develop a framework to analyze the information content of X-ray measurement data for the task of material discrimination. This task-specific information (TSI) analysis provides valuable information for system design and optimization. We employ Bhattacha ... Full text Cite

Modeling realistic virtual objects within a high-throughput X-ray simulation framework

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2020 X-ray simulation of realistic object models is relevant across all areas in which X-ray systems are employed, including medical, industrial, and security applications. A particularly exciting area of impact stems from the development of machine learning ap ... Full text Cite

Using inkjet 3D printing to create contrast-enhanced textured physical phantoms for CT

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2019 Anthropomorphic phantoms can serve as anatomically structured tools for assessing clinical computed tomography (CT) imaging systems. The aim of this project is to create highly customized 3D inkjet-printed, contrast-enhanced physical liver phantoms for use ... Full text Cite

Modeling real world system geometry and detector response within a high-throughput X-ray simulation framework

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2019 Simulations of x-ray scanners have the potential to aid in the design and understanding of system performance. We have previously shown the usefulness of a high-throughput simulation framework in pursuit of information theoretic analysis of x-ray systems e ... Full text Cite

Motivations and methods for the analysis of multi-modality X-ray systems for explosives detection

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2019 Transmission-based imaging and X-ray diffraction-based material analysis have largely developed independently. However, for a variety of applications ranging from in-vivo soft tissue analysis to concealed explosives detection, it is necessary to realize hi ... Full text Cite

Simulation-based X-ray system design and analysis: Past, present, and future

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2019 Since 2013, a Duke University / University of Arizona collaboration has been investigating how to optimize the hardware design of aviation-security x-ray systems. The goal of the effort is to develop a detection-algorithmagnostic approach that focuses on t ... Full text Cite

Prototype coded aperture miniature mass spectrometer for environmental sensing

Conference AQM 2019 - Air Quality Measurement Methods and Technology Conference 2019 · January 1, 2019 © 2019 Air and Waste Management Association. All rights reserved. In summary, this paper shows the design and initial performance characterization of a coded aperture miniature mass spectrometer for environmental sensing (CAMMS-ES). CAMMS-ES incorporates s ... Cite

Prototype coded aperture miniature mass spectrometer for environmental sensing

Conference Aqm 2019 Air Quality Measurement Methods and Technology Conference 2019 · January 1, 2019 In summary, this paper shows the design and initial performance characterization of a coded aperture miniature mass spectrometer for environmental sensing (CAMMS-ES). CAMMS-ES incorporates spatial aperture coding to break the throughput vs. resolution trad ... Cite

Single-shot multispectral color imaging through scattering media

Conference Optics Infobase Conference Papers · January 1, 2019 Memory effect (ME) imaging forms high-fidelity, diffraction-limited images through scatter without any prior knowledge. Here we demonstrate compressive ME imaging by extracting a color image of a scatter-obscured object from a single coded monochrome expos ... Full text Cite

Prototype coded aperture miniature mass spectrometer using a cycloidal sector mass analyzer

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 19, 2018 Link to item Cite

3D printed anthropomorphic physical phantom for mammography and DBT with high contrast custom materials, lesions, and uniform chest wall region

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2018 Anthropomorphic breast phantoms mimic anatomy to evaluate the performance of clinical mammography and digital breast tomosynthesis (DBT) systems. Our goal is to make a phantom that mimics clinically relevant appearance of a patient to allow for improved im ... Full text Cite

Channel-first design of modulated polarimeters

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2018 Multi-domain modulated polarimeters combine carriers on different domains to exploit the bandwidth of the measurement system. However, the inevitable systematic errors in polarimeters will degrade their bandwidth performance, so we developed a new type of ... Full text Cite

An information theoretic approach to system optimization accounting for material variability

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2018 Differentiating material anomalies requires a measurement system that can reliably inform the user/classifier of pertinent material characteristics. In past work, we have developed a simulation framework capable of making simulated x-ray transmission and s ... Full text Cite

Third generation anthropomorphic physical phantom for mammography and DBT: Incorporating voxelized 3D printing and uniform chest wall QC region

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2017 Physical breast phantoms provide a standard method to test, optimize, and develop clinical mammography systems, including new digital breast tomosynthesis (DBT) systems. In previous work, we produced an anthropomorphic phantom based on 500x500x500 μm breas ... Full text Cite

Creating an experimental testbed for information-theoretic analysis of architectures for x-ray anomaly detection

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2017 Anomaly detection requires a system that can reliably convert measurements of an object into knowledge about that object. Previously, we have shown that an information-theoretic approach to the design and analysis of such systems provides insight into syst ... Full text Cite

Dynamically coded memory effect imaging

Conference Optics Infobase Conference Papers · January 1, 2017 The optical memory effect has recently been used to image static scenes through opaque media. By using spatio-temporal coding, we realize memory effect video of dynamic scenes from a single, compressive measurement. ... Full text Cite

Image reconstruction for view-limited x-ray CT in baggage scanning

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2017 X-ray CT based baggage scanners are widely used in security applications. Recently, there has been increased interest in view-limited systems which can improve the scanning throughput while maintaining the threat detection performance. However as very few ... Full text Cite

Shape threat detection via adaptive computed tomography

Conference SPIE Proceedings · May 12, 2016 Full text Cite

Aviation security x-ray detection challenges

Conference SPIE Proceedings · May 12, 2016 Full text Cite

Direction of arrival (DOA) estimation system using 3D printed Luneburg lens

Conference 2016 IEEE Aces International Conference on Wireless Information Technology Icwits 2016 and System and Applied Computational Electromagnetics Aces 2016 Proceedings · May 4, 2016 A novel direction of arrival (DOA) estimation system based on a broadband 3D printed Luneburg lens is reported in this paper. Using the property of a Luneburg lens that the focus point of an incident plane wave is at the opposite side on the surface of the ... Full text Cite

Design, fabrication, and implementation of voxel-based 3D printed textured phantoms for task-based image quality assessment in CT

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2016 In x-ray computed tomography (CT), task-based image quality studies are typically performed using uniform background phantoms with low-contrast signals. Such studies may have limited clinical relevancy for modern non-linear CT systems due to possible influ ... Full text Cite

Second generation anthropomorphic physical phantom for mammography and DBT: Incorporating voxelized 3D printing and inkjet printing of iodinated lesion inserts

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2016 Physical phantoms are needed for the evaluation and optimization of new digital breast tomosynthesis (DBT) systems. Previously, we developed an anthropomorphic phantom based on human subject breast CT data and fabricated using commercial 3D printing. We no ... Full text Cite

Information-theoretic analysis of x-ray photoabsorption based threat detection system for check-point

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 In this work we present an information-theoretic framework for a systematic study of checkpoint x-ray systems using photoabsorption measurements. Conventional system performance analysis of threat detection systems confounds the effect of the system archit ... Full text Cite

Rapid GPU-based simulation of x-ray transmission, scatter, and phase measurements for threat detection systems

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 To support the statistical analysis of x-ray threat detection, we developed a very high-throughput x-ray modeling framework based upon GPU technologies and have created three different versions focusing on transmission, scatter, and phase. The simulation o ... Full text Cite

Information-theoretic analysis of x-ray scatter and phase architectures for anomaly detection

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 Conventional performance analysis of detection systems confounds the effects of the system architecture (sources, detectors, system geometry, etc.) with the effects of the detection algorithm. Previously, we introduced an information-theoretic approach to ... Full text Cite

Adaptive architectures for spectral processing

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 Introduction of adaptive components into optical sensing architectures can facilitate powerful new modes of operation that blend acquisition and exploitation. I discuss three spectral applications where such gains have been validated experimentally by my r ... Full text Cite

Computational hyperspectral unmixing using the AFSSI-C

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 We have previously introduced a high throughput multiplexing computational spectral imaging device. The device measures scalar projections of pseudo-arbitrary spectral filters at each spatial pixel. This paper discusses simulation and initial experimental ... Full text Cite

Introduction

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 Full text Cite

Hyperspectral Unmixing using the AFSSI-C

Conference Optics Infobase Conference Papers · January 1, 2015 We investigate the use of the Adaptive Feature Specific Spectral Imaging Classifier (AFSSI-C) architecture to perform spectral unmixing. Through simulations using a variety of static coding schemes, we demonstrate that the AFSSI-C outperforms traditional h ... Cite

Adaptive Spectral Imaging Classification

Conference Imaging and Applied Optics 2015 · 2015 Full text Cite

Terahertz emission properties of butterfly-shaped photoconductive antennas based on LT-GaAs and SI-GaAs substrates

Conference International Conference on Infrared Millimeter and Terahertz Waves Irmmw Thz · November 13, 2014 Photoconductive antennas (PCA) (one of the most commonly used terahertz emitters) have limited performance (e.g. low output power) and as such, do not fully meet the increasing needs of applications. This work attempts to find a route to further improve th ... Full text Cite

Millimeter wave luneburg lens antenna fabricated by polymer jetting rapid prototyping

Conference International Conference on Infrared Millimeter and Terahertz Waves Irmmw Thz · November 13, 2014 In this paper, the design, fabrication and characterization of a 3D printed Luneburg lens antenna working at Ka and Q band are proposed. Gradient index control of the lens is based on the mixing ratio of air voids and polymer. The effective dielectric cons ... Full text Cite

Terahertz digital holographic imaging of visibly opaque printed dielectrics

Conference International Conference on Infrared Millimeter and Terahertz Waves Irmmw Thz · November 13, 2014 Terahertz digital off-axis holography has been demonstrated as a non-destructive imaging tool for three-dimensional (3D) printed structures. Digital holographic reconstructions from two structures were used to measure the imager's modulation transfer funct ... Full text Cite

Theoretical and experimental study of a terahertz time-domain spectrometer based on photoconductive antenna

Conference 2014 United States National Committee of Ursi National Radio Science Meeting Usnc Ursi Nrsm 2014 · October 16, 2014 We construct a terahertz time-domain spectrometer (THz-TDS) system based on photoconductive antenna (PCA). A 800 nm Ti:sapphire femtosecond laser with 80 MHz repetition rate provides the pump and probe laser pulse, which has a 45 fs pulse width (as short a ... Full text Cite

Experimental validation of the adaptive feature-specific spectral imaging classifier (AFSSI-C)

Conference Frontiers in Optics, FiO 2014 · October 14, 2014 © 2014 Optical Society of America. We present experimental results for the Adaptive Feature-Specific Spectral Imaging Classifier (AFSSI-C) that are in excellent quantitative agreement with simulation. Performance gains >1000x relative to conventional appro ... Cite

Experimental validation of the adaptive feature-specific spectral imaging classifier (AFSSI-C)

Conference Frontiers in Optics Fio 2014 · October 14, 2014 We present experimental results for the Adaptive Feature-Specific Spectral Imaging Classifier (AFSSI-C) that are in excellent quantitative agreement with simulation. Performance gains >1000x relative to conventional approaches are predicted for expanded sy ... Full text Cite

Comparison of photoconductive antenna performance on LT-GaAs and SI-GaAs substrates

Conference IEEE Antennas and Propagation Society AP S International Symposium Digest · September 18, 2014 In this work, butterfly shaped photoconductive antennas (PCAs) on low-temperature grown (LT) GaAs and semi-insulating (SI) GaAs substrate as terahertz (THz) emitters are experimentally characterized and compared. Dependences of the THz radiated field on th ... Full text Cite

Efficient model-based tonemapping of high dynamic range gigapixel images

Conference Optics Infobase Conference Papers · January 1, 2013 We present a technique to address the tonemapping of high dynamic range (HDR) gigapixel images. The proposed method relies on extracting low-dimensional models from lowresolution proxy images, and can be efficiently implemented in a parallel manner. © OSA ... Full text Cite

Calibration challenges and initial experimental demonstration of an adaptive, feature-specific spectral imaging classifier

Conference Optics Infobase Conference Papers · January 1, 2013 We describe the calibration challenges associated with a computational spectral imaging classifier and present initial experimental results. We also discuss planned system improvements to address these calibration challenges and observed performance issues ... Full text Cite

Color image formation for multiscale gigapixel imaging

Conference Optics Infobase Conference Papers · January 1, 2013 We present the current development of the image formation pipeline for color gigapixel images obtained by the AWARE-10 multiscale camera.We introduce a camera simulator, the modifications to the scalable pipeline, and the challenges for creating seamless c ... Full text Cite

Adaptive feature-specific spectral imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · July 23, 2012 We present an architecture for rapid spectral classification in spectral imaging applications. By making use of knowledge gained in prior measurements, our spectral imaging system is able to design adaptive feature-specific measurement kernels that selecti ... Full text Cite

Electromagnetic crystal (EMXT)-based THz components

Conference Proceedings of SPIE the International Society for Optical Engineering · June 9, 2011 Various all-dielectric electromagnetic crystal (EMXT) based THz components, including filter/reflector, waveguide, antenna, and transition structure to planar circuits are proposed and simulated. Several of them have been fabricated via a THz rapid prototy ... Full text Cite

Image formation in multiscale optical systems

Conference Optics InfoBase Conference Papers · January 1, 2011 We present image formation (IF) strategies developed for multiscale imaging systems. In this context, IF takes advantage of significant prior knowledge of array geometry and relies on parallelizable algorithms to handle the high data bandwidth. © 2011 OSA. ... Cite

Terahertz electromagnetic crystal (EMXT) based waveguide and horn antenna

Conference Irmmw Thz 2010 35th International Conference on Infrared Millimeter and Terahertz Waves Conference Guide · November 30, 2010 All-dielectric Terahertz waveguides based on hollow-core EMXT fiber are fabricated via THz rapid prototyping using polymer jetting technique. Several waveguides of identical cross-section and differing lengths are characterized by THz time-domain spectrosc ... Full text Cite

Hollow-core electromagnetic band gap (EBG) waveguide fabricated by rapid prototyping for low-loss terahertz guiding

Conference IEEE MTT S International Microwave Symposium Digest · October 15, 2010 An all-dielectric THz waveguide has been designed, fabricated and characterized. The design is based on electromagnetic band gap (EBG) structures, and the fabrication is implemented with polymer-jetting rapid prototyping method. Measurement results show go ... Full text Cite

Investigation of several terahertz electromagnetic band gap structures

Conference Microwave and Optical Technology Letters · March 1, 2010 Several THz electromagnetic band gap (EBG) structures are investigated and demonstrated. Various design, fabrication, and characterization methods and techniques are utilized and compared. These THz EBG structures may enable future high performance EBG bas ... Full text Cite

All-dielectric low-loss Terahertz waveguide fabricated by rapid prototyping

Conference 34th International Conference on Infrared Millimeter and Terahertz Waves Irmmw Thz 2009 · December 31, 2009 An all-dielectric Terahertz waveguide is designed based on hollow-core photonic crystal fiber. Simulation shows a waveguide transmission loss as low as 0.019 dB/mm near 140 GHz with a working bandwidth of approximately 18 GHz. Several waveguides of identic ... Full text Cite

Adaptive spectroscopy: Towards adaptive spectral imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · May 20, 2008 Spectral imaging is an emerging tool for defense and security applications because it provides compositional information about the objects in a scene. The underlying task-measuring a 3-D dataset using a 2-D detector array-is challenging, and straightforwar ... Full text Cite

Compressive spectral imaging and multiscale reconstruction methods

Conference Optics InfoBase Conference Papers · January 1, 2007 In this work we develop a single-shot, dual-disperser spectral imaging system and associated multiscale photon-limited multispectral reconstruction methods that have been designed to exploit the emerging theory of compressive sensing. © 2007 Optical Societ ... Cite

Compressive spectral imaging and multiscale reconstruction methods

Conference Optics Infobase Conference Papers · January 1, 2007 In this work we develop a single-shot, dual-disperser spectral imaging system and associated multiscale photon-limited multispectral reconstruction methods that have been designed to exploit the emerging theory of compressive sensing. © 2007 Optical Societ ... Full text Cite

Quantitative dynamic range management techniques for spectroscopic detection and estimation

Conference Optics Infobase Conference Papers · January 1, 2007 Introduction of active filters into spectrometer design results in flexible systems that are insensitive to source/detector dynamic range mismatch, thereby allowing detection of spectral features that were previously below the detection limit. © 2007 Optic ... Full text Cite

Integrated sensing and processing of Raman spectra for in vivo BAC measurement

Conference ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH · June 1, 2006 Link to item Cite

Longwave Infrared (LWIR) Coded Aperture Dispersive Spectrometer

Conference Optics Infobase Conference Papers · January 1, 2006 We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array as the detector plane. We present experimental results of absorption spectroscopy for a variety of sources. ... Cite

Multimodal, multiplex Raman spectrometer for weak, incoherent sources

Conference Optics Infobase Conference Papers · January 1, 2005 Raman spectroscopy in bio-materials is complicated by fluorescence and scattering. We have developed a multimodal, multiplex spectrometer that overcomes these difficulties. We are currently constructing a second generation prototype for in-vivo Raman spect ... Full text Cite

Multiplex design for high-performance microspectrometers

Conference Optics Infobase Conference Papers · January 1, 2005 The volume of spectrometers can be drastically reduced through the use of multiplex measurement. Reductions of 3-5 orders of magnitude are possible. This has the potential to drastically effect manufacturing and deployment costs. ©2005 Optical Society of A ... Full text Cite

Coded-aperture, multi-wavelength Raman spectroscopy for ethanol detection in biological samples

Conference Proceedings of the 8th Joint Conference on Information Sciences, Vols 1-3 · January 1, 2005 Link to item Cite

Static, multimodal, multiplex spectrometer design for weak, incoherent sources

Conference Optics Infobase Conference Papers · January 1, 2004 We present a flexible design for a static, multimodal, multiplex spectrometer which is optimized for the weak incoherent sources that are common in biomedical applications. Simultaneous high throughput and resolution are achieved in a single-shot measureme ... Cite

Multimodal, multiplex Raman spectrometry for detection of ethanol in blood and tissue

Conference Optics Infobase Conference Papers · January 1, 2004 We investigate the application of static, multimodal, multiplex spectrometers to the detection of the Raman spectrum of ethanol in blood and tissue. These spectrometers are optimized for use with weak, incoherent sources, and enable relatively high sensiti ... Cite

Stability of a strongly-attractive, two-component Fermi gas

Conference Optics Infobase Conference Papers · January 1, 2003 Using a simple model, we show that a strongly-attractive, two-component Fermi gas of atoms should be mechanically stable as a consequence of unitarity. We demonstrate this stability experimentally in a degenerate gas of 6Li atoms. ... Cite

Measurement of the mean-field interaction in a strongly-interacting Fermi gas

Conference Optics Infobase Conference Papers · January 1, 2003 We release a strongly-interacting, two-component Fermi gas from an optical trap. From the release energy, we determine an important, universal many-body parameter: the ratio of the mean-field energy to the local Fermi energy. ... Cite

Observation of hydrodynamic expansion of a strongly-interacting Fermi gas: Signature of superfluidity?

Conference Optics Infobase Conference Papers · January 1, 2003 We observe dramatic anisotropic expansion of a strongly-interacting Fermi gas upon release from an optical trap. The observed hydrodynamic behavior is a possible first signature of the onset of a new type of high-temperature superfluidity. ... Cite

Optically-trapped Fermi gas

Conference Technical Digest Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference QELS 2001 · January 1, 2001 Summary form only given. Cold, dense gases of fermions offer exciting new opportunities for fundamental studies of quantum degeneracy, collective behavior, and superfluidity. Fermionic 6Li has been the subject of numerous theoretical treatments. ... Full text Cite

Modeling the evaporative cooling of fermionic atoms in an optical trap

Conference Technical Digest Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference QELS 2001 · January 1, 2001 Summary form only given. Evaporative cooling of atoms in an optical trap has recently received renewed attention as a means for obtaining degeneracy in an optically trapped bosonic Cs vapor as well as a fermionic Li gas. We have developed a new model descr ... Full text Cite