Journal ArticleTranslational vision science & technology · March 2025
PurposeOptical coherence tomography (OCT) has become an indispensable tool for the detection and analysis of diseased retinal tissue. Recent advances in reducing the size and cost of OCT systems have aimed at expanding their use for new applicatio ...
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Journal ArticleBiomedical optics express · February 2025
Low-cost optical coherence tomography (OCT) has shown promise in increasing access to noninvasive retinal imaging at the point of care, especially in low-resource environments. A next-generation low-cost OCT system is presented which improves performance o ...
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Journal ArticleOptica · January 20, 2025
The scattering and absorption of light within biological tissue severely limits the penetration depth of optical imaging techniques. Recently, it has been found that water-soluble, strongly absorbing dye molecules, such as tartrazine, can achieve in vivo t ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · November 2024
Understanding cellular responses to mechanical environmental stimuli is important for cellular mechanotransduction studies. While fluorescence microscopy has been used for aiding mechanotransduction research due to its molecular sensitivity, the ability of ...
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Journal ArticleBiophotonics International · November 1, 2024
OCT systems can differentiate between skin lesions and other dermatological conditions, and new approaches seek to enhance existing instrumentation. OCT is a compelling imaging modality for dermatology and biomedicine due to its capability to noninvasively ...
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Journal ArticleJ Biophotonics · September 2024
Screening for colorectal cancer (CRC) with colonoscopy has improved patient outcomes; however, it remains the third leading cause of cancer-related mortality, novel strategies to improve screening are needed. Here, we propose an optical biopsy technique ba ...
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Journal ArticleOptics letters · August 2024
We demonstrate the use of a novel, to the best of our knowledge, localization algorithm for digitally refocusing fluorescence images from a three-dimensional cell culture. Simultaneous phase and fluorescence intensity images are collected through a multimo ...
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Journal ArticleOptics express · June 2024
Endoscopic angle-resolved light scattering methods have been developed for early cancer detection but they typically require multi-element coherent fiber optic bundles to recover scattering distributions from tissues. Recent work has focused on using a sin ...
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Journal ArticleBiomedical optics express · March 2024
Angle-resolved low-coherence interferometry (a/LCI) is an optical technique that enables depth-specific measurements of nuclear morphology, with applications to detecting epithelial cancers in various organs. Previous a/LCI setups have been limited by cost ...
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ConferenceMicroscopy Histopathology and Analytics Microscopy 2024 in Proceedings Optica Biophotonics Congress Biomedical Optics 2024 Translational Microscopy Oct Ots Brain Part of Optica Biophotonics Congress Biomedical Optics · January 1, 2024
We demonstrate the use of quantitative phase microscopy to localize defocused fluorescent images with the transport of intensity equation. Specifically, we demonstrate a technique for digitally refocusing images from three-dimensional cell cultures. ...
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ConferenceOptical Coherence Tomography, OCT 2024 in Proceedings Optica Biophotonics Congress: Biomedical Optics 2024, Translational, Microscopy, OCT, OTS, BRAIN - Part of Optica Biophotonics Congress: Biomedical Optics · January 1, 2024
Low-cost OCT has point-of-care diagnostic potential for retinal measurements related to neurodegenerative diseases in low resource environments. We present methods for improved retinal imaging in low-cost OCT via implementation of balanced detection. ...
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ConferenceOptical Coherence Tomography Oct 2024 in Proceedings Optica Biophotonics Congress Biomedical Optics 2024 Translational Microscopy Oct Ots Brain Part of Optica Biophotonics Congress Biomedical Optics · January 1, 2024
We propose the use of spectroscopic OCT to characterize nuclear signatures of colon polyps ex vivo for early colorectal cancer detection. We justify using SOCT by accurately measuring the size of 4.78 µm polystyrene beads. ...
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ConferenceOptical Coherence Tomography Oct 2024 in Proceedings Optica Biophotonics Congress Biomedical Optics 2024 Translational Microscopy Oct Ots Brain Part of Optica Biophotonics Congress Biomedical Optics · January 1, 2024
Low-cost OCT has point-of-care diagnostic potential for retinal measurements related to neurodegenerative diseases in low resource environments. We present methods for improved retinal imaging in low-cost OCT via implementation of balanced detection. ...
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Journal ArticleInternational journal of molecular sciences · July 2023
Sickle cell disease (SCD) is an inherited hematological disorder associated with high mortality rates, particularly in sub-Saharan Africa. SCD arises due to the polymerization of sickle hemoglobin, which reduces flexibility of red blood cells (RBCs), causi ...
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Journal ArticleBiophysical journal · April 2023
Optical methods for examining cellular structure based on endogenous contrast rely on analysis of refractive index changes to discriminate cell phenotype. These changes can be visualized using techniques such as phase contrast microscopy, detected by light ...
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ConferenceNovel Techniques in Microscopy NTM 2023 · January 1, 2023
We demonstrate a novel technique for calculating the fractal dimension of adherent cells using multiscale Quantitative Phase Imaging information. We examine the relationship between this measurement and disorder strength across different cell lines. ...
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ConferenceNovel Techniques in Microscopy NTM 2023 · January 1, 2023
Two-wavelength phase microscopy enables quantification of hemoglobin concentration and height of fast-flowing cells in a flow cytometer. This approach shows great potential for point-of-care diagnosis of blood disorders. ...
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ConferenceBio Optics Design and Application in Proceedings Biophotonics Congress Optics in the Life Sciences 2023 Oma NTM Boda Omp Brain 2023 · January 1, 2023
We propose to use holographic cytometry to evaluate sickle cell disease patient samples and develop artificial intelligence that can screen for sickling phenotypes. ...
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Journal ArticleDigestive diseases and sciences · October 2022
Background and aimsEndoscopic surveillance of Barrett's esophagus (BE) by white light examination is insufficient to diagnose dysplastic change. In this work, we describe an optical imaging method to obtain high-resolution cross-sectional imaging ...
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ConferenceOptics Infobase Conference Papers · January 1, 2022
Demonstration of quantitative phase microscopy and Förster resonance energy transfer for analyzing molecular and structural information simultaneously. We focus on signaling pathways and sub-cellular structure for endothelial cells exposed to various flows ...
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ConferenceOptics Infobase Conference Papers · January 1, 2022
We use three Quantitative Phase Imaging modalities to measure morphological properties of adherent cells. We aim to show that cellular disorder strength differs between systems but can be directly compared by considering system resolution. ...
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ConferenceLecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics · January 1, 2022
Optical coherence tomography (OCT) is widely used for detection of ophthalmic diseases, such as glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy. Using a low-coherence-length light source, OCT is able to achieve high axial resolut ...
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Journal ArticleBiomedical optics express · December 2021
For many clinical applications, such as dermatology, optical coherence tomography (OCT) suffers from limited penetration depth due primarily to the highly scattering nature of biological tissues. Here, we present a novel implementation of dual-axis optical ...
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Journal ArticleFrontiers in Physics · November 30, 2021
Holographic cytometry is an ultra-high throughput quantitative phase imaging modality that is capable of extracting subcellular information from millions of cells flowing through parallel microfluidic channels. In this study, we present our findings on the ...
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Journal ArticleBiomedical optics express · October 2021
Optical coherence tomography (OCT) is used for diagnosis of esophageal diseases such as Barrett's esophagus. Given the large volume of OCT data acquired, automated analysis is needed. Here we propose a bilateral connectivity-based neural network for in ...
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Journal ArticleCells · September 17, 2021
Holographic cytometry is introduced as an ultra-high throughput implementation of quantitative phase imaging of single cells flowing through parallel microfluidic channels. Here, the approach was applied for characterizing the morphology of individual red ...
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Journal ArticleJ Biomed Opt · September 2021
SIGNIFICANCE: The current gold standard for monitoring small intestinal transplant (IT) rejection is endoscopic visual assessment and biopsy of suspicious lesions; however, these lesions are only superficially visualized by endoscopy. Invasive biopsies pro ...
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Journal ArticleBiomedical optics express · August 2021
We present a machine learning method for detecting and staging cervical dysplastic tissue using light scattering data based on a convolutional neural network (CNN) architecture. Depth-resolved angular scattering measurements from two clinical trials were u ...
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ConferenceOptics Infobase Conference Papers · January 1, 2021
We demonstrate the use of quantitative phase microscopy and Förster resonance energy transfer for analyzing molecular and structural information simultaneously. Specifically, we focus on effects of ion channel modulation on signaling pathways and sub-cellu ...
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ConferenceOptics Infobase Conference Papers · January 1, 2021
We propose to use holographic cytometry to collect high throughput data on flowing tumorigenic and nontumorigenic cells. We aim to characterize different cell lines using machine learning and morphological parameters analysis. ...
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Journal ArticleBiomedical optics express · September 2020
We present a prospective clinical study using angle-resolved low-coherence interferometry (a/LCI) to detect cervical dysplasia via depth resolved nuclear morphology measurements. The study, performed at the Jacobi Medical Center, compares 80 a/LCI optical ...
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Journal ArticleBiomedical optics express · August 2020
Angle-resolved low-coherence interferometry (a/LCI) measures depth-resolved angular scattering for cell nuclear morphology analysis. 2D a/LCI, developed to collect across two scattering planes, is currently limited by the lack of spatial scanning. Here we ...
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Journal ArticleAPL photonics · July 2020
We demonstrate reconstruction of angle-resolved optical backscattering after transmission through a multimode fiber. Angle-resolved backscattering is an important tool for particle sizing, and has been developed as a diagnostic modality for detecting epith ...
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Journal ArticleSci Rep · May 13, 2020
We acquired depth-resolved light scattering measurements from the retinas of triple transgenic Alzheimer's Disease (3xTg-AD) mice and wild type (WT) age-matched controls using co-registered angle-resolved low-coherence interferometry (a/LCI) and optical co ...
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ConferenceOptics Infobase Conference Papers · January 1, 2020
We have recently developed a portable, low cost OCT system. This presentation will present an updated design for the optical engine and discuss application in ophthalmology and extensions to fields such as orthopedics, gastroenterology and gynecology where ...
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ConferenceOptics Infobase Conference Papers · January 1, 2020
We demonstrate the use of a transmission matrix approach to reconstruct angular backscattering profiles through a single multimode fiber, with an accurate determination of the scatterer's size based on Mie theory. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2020
We demonstrate the first clinical implementation of a scanning method to perform angle-resolved low-coherence interferometry (a/LCI) to detect cervical dysplasia over a large area without repositioning. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2020
We present the integration of spatial scanning into a two-dimensional angle-resolved low-coherence interferometry system. We demonstrate collection of two-dimensional angular scattering over a three-dimensional spatial volume for a variety of samples. ...
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ConferenceFrontiers in Optics Proceedings Frontiers in Optics Laser Science Aps Dls · September 8, 2019
We present a method for expanding the scanning volume of a dual-axis optical coherence tomography system (DA-OCT). The modified design increases the lateral scanning area by a factor of 25 and greatly enhances imaging performance in depth using dynamic foc ...
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Journal ArticleBiophysical journal · August 2019
Many approaches have been developed to characterize cell elasticity. Among these, atomic force microscopy (AFM) combined with modeling has been widely used to characterize cellular compliance. However, such approaches are often limited by the difficulties ...
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Journal ArticleOptica · April 2019
Light scattering has become a common biomedical research tool, enabling diagnostic sensitivity to myriad tissue alterations associated with disease. Light-tissue interactions are particularly attractive for diagnostics due to the variety of contrast mechan ...
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Journal ArticleJournal of biophotonics · February 2019
In recent years, significant work has been devoted to the use of angle-resolved elastic scattering for the extraction of nuclear morphology in tissue. By treating the nucleus as a Mie scattering object, techniques such as angle-resolved low-coherence inter ...
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ConferenceProgress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2019
Optical imaging techniques generally offer shallow penetration depths due to high scattering in biological tissue. We have recently developed dual-axis optical coherence tomography (DA-OCT) for interferometric imaging at extended depths. By illuminating an ...
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Journal ArticleMicrosyst Nanoeng · 2019
Changes in the deformability of red blood cells can reveal a range of pathologies. For example, cells which have been stored for transfusion are known to exhibit progressively impaired deformability. Thus, this aspect of red blood cells has been characteri ...
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ConferenceOptics Infobase Conference Papers · January 1, 2019
We demonstrate the use of a transmission matrix approach to reconstruct angular scattering profiles measured through an individual multimode fiber, with an eye towards applications in tissue scattering and Mie theory-based analysis. ...
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Journal ArticleJournal of biophotonics · December 2018
Apoptotic mechanisms are often dysregulated in cancerous phenotypes. Additionally, many anticancer treatments induce apoptosis and necrosis, and the monitoring of this apoptotic activity can allow researchers to identify therapeutic efficiency. Here, we in ...
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Journal ArticleAPL photonics · November 2018
Quantitative phase imaging (QPI) offers high optical path length sensitivity, probing nanoscale features of live cells, but it is typically limited to imaging just few static cells at a time. To enable utility as a biomedical diagnostic modality, higher th ...
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Journal ArticleJournal of biophotonics · June 2018
Recently, Maxim A. Yurkin commented on our paper "Is the nuclear refractive index lower than cytoplasm? Validation of phase measurements and implications for light scattering technologies" as well as on a complementary study "Cell nuclei have lower refract ...
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Journal ArticleBiomedical optics express · March 2018
Optical coherence tomography (OCT) is a widely used biomedical imaging tool, primarily in ophthalmology to diagnose and stage retinal diseases. In order to increase access for a wider range of applications and in low resource settings, we developed a porta ...
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Journal ArticleOptical Materials Express · March 1, 2018
Distinguishing authentic and artificial Chinese freshwater pearls involves various tools and techniques, based primarily on visual inspection and spectroscopy. These methods are highly variable and thus not statistically reliable. This study investigates t ...
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Journal ArticleCarcinogenesis · February 2018
Cancer cells consistently exhibit decreased stiffness; however, the onset and progression of this change have not been characterized. To study the development of cell stiffness changes, we evaluated the shear stiffness of populations of cells during transf ...
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ConferenceOptics Infobase Conference Papers · January 1, 2018
We present a low-cost (under $7,200), portable OCT system to improve ease of access outside of large eye centers. We demonstrate comparable imaging performance to current commercial OCT systems in ex vivo tissue samples. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2018
We present the design of a scanning a/LCI instrument which uses the depth-resolved reflectivity profile to identify the cervical transformation zone and guide a/LCI measurements of nuclear morphology for detection of cervical dysplasia in vivo. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2018
OCT is a widely used biomedical imaging tool, primarily to diagnose and stage retinal diseases. To increase access, we developed a portable, low-cost OCT system with comparable imaging performance to commercially available systems. ...
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Journal ArticleJournal of biophotonics · December 2017
The refractive index (RI) of biological materials is a fundamental parameter for the optical characterization of living systems. Numerous light scattering technologies are grounded in a quantitative knowledge of the refractive index at cellular and subcell ...
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Journal ArticleBiomedical optics express · December 2017
Though structured illumination (SI) microscopy is a popular imaging technique conventionally associated with fluorescent super-resolution, recent works have suggested its applicability towards sub-diffraction resolution coherent imaging with quantitative e ...
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Journal ArticleOptics letters · November 2017
Angle-resolved low-coherence interferometry (a/LCI) detects precancer by enabling depth-resolved measurements of nuclear morphology in vivo. A significant limitation of a/LCI is the point-probe nature of the method, sampling <0.5 mm2 before pro ...
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Journal ArticleJournal of Optics United Kingdom · August 22, 2017
Optofluidics, nominally the research area where optics and fluidics merge, is a relatively new research field and it is only in the last decade that there has been a large increase in the number of optofluidic applications, as well as in the number of rese ...
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Journal ArticleOpt Lett · June 15, 2017
We have developed dual-axis optical coherence tomography (DA-OCT) which enables deep tissue imaging by using a novel off-axis illumination/detection configuration. DA-OCT offers a 100-fold speed increase compared with its predecessor, multispectral multipl ...
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Journal ArticleOptica · May 20, 2017
To probe biological questions with significant biophysical, biochemical, and molecular components, an imaging solution compatible with both endogenous and molecular 3D imaging may be necessary. In this work, we show that structured illumination (SI) micros ...
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Journal ArticleBiomedical optics express · May 2017
Sub-diffraction resolution imaging has played a pivotal role in biological research by visualizing key, but previously unresolvable, sub-cellular structures. Unfortunately, applications of far-field sub-diffraction resolution are currently divided between ...
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Journal ArticleInternational journal of cancer · March 2017
This study sought to establish the feasibility of using in situ depth-resolved nuclear morphology measurements for detection of cervical dysplasia. Forty enrolled patients received routine cervical colposcopy with angle-resolved low coherence interferometr ...
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Journal ArticleJournal of pharmaceutical sciences · February 2017
Confocal Raman spectroscopy was implemented in a new label-free technique to quantify molecular diffusion coefficients within gels. A leading anti-HIV drug, tenofovir, was analyzed in a clinical microbicide gel. The gel was tested undiluted, and in 10%-50% ...
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Journal ArticleBiophysical journal · February 2017
There have been sustained efforts on the part of cell biologists to understand the mechanisms by which cells respond to mechanical stimuli. To this end, many rheological tools have been developed to characterize cellular stiffness. However, measurement of ...
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Journal ArticlePloS one · January 2017
Vaginally applied microbicide products offer a female-controlled strategy for preventing sexual transmission of HIV. Microbicide transport processes are central to their functioning, and there is a clear need for a better understanding of them. To contribu ...
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ConferenceOptics Infobase Conference Papers · January 1, 2017
Dual Axis (DA) spectroscopic optical coherence tomography enables deep tissue imaging and provides diagnostic information. Here it is applied to a McFarlane rat flap model, which exhibits a gradient in tissue injury along the flap length. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2017
Quantitative phase imaging uses interferometry to obtain nanoscale information on live cells. Here we describe its use for disease diagnosis and analysis of cell biomechanical properties. ...
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Journal ArticleBiomed Opt Express · October 1, 2016
We have developed frequency domain multispectral multiple scattering low coherence interferometry (ms2/LCI) for deep imaging of absorption and scattering contrast. Using tissue-mimicking phantoms that match the full scattering phase function of human derma ...
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Journal ArticleSci Rep · April 18, 2016
Plasmodium falciparum infection causes structural and biochemical changes in red blood cells (RBCs). To quantify these changes, we apply a novel optical technique, quantitative phase spectroscopy (QPS) to characterize individual red blood cells (RBCs) duri ...
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ConferenceOptics Infobase Conference Papers · April 18, 2016
Oxygenation of hemolyzed blood was measured with multispectral multiple-scattering low coherence interferometry revealing a high correlation (r2=0.961) with gold-standard spectrophotometer measurements. ...
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ConferenceOptics Infobase Conference Papers · April 18, 2016
Here we present the analysis of two dimensional angle-resolved low coherence interferometry (2D a/LCI) measurements co-registered with optical coherence tomography (OCT) imaging to guide the a/LCI measurements on an esophageal cancer rat model. ...
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ConferenceOptics Infobase Conference Papers · April 18, 2016
Here we present the analysis of two dimensional angle-resolved low coherence interferometry (2D a/LCI) measurements co-registered with optical coherence tomography (OCT) imaging to guide the a/LCI measurements on an esophageal cancer rat model. ...
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ConferenceOptics Infobase Conference Papers · April 18, 2016
Oxygenation of hemolyzed blood was measured with multispectral multiple-scattering low coherence interferometry revealing a high correlation (r2=0.961) with gold-standard spectrophotometer measurements. ...
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Journal ArticleBiomed Opt Express · April 1, 2016
Angle-resolved low coherence interferometry (a/LCI) is an optical technique used to measure nuclear morphology in situ. However, a/LCI is not an imaging modality and can produce ambiguous results when the measurements are not properly oriented to the tissu ...
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Journal ArticleOptics letters · January 2016
We present a platform for detecting cellular deformations from mechanical stimuli, such as fluid shear stress, using rapid quantitative phase imaging. Rapid quantitative phase imaging was used to analyze changes in the optical path length of adherent skin ...
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Journal ArticlePLoS One · 2016
Malaria detection through microscopic examination of stained blood smears is a diagnostic challenge that heavily relies on the expertise of trained microscopists. This paper presents an automated analysis method for detection and staging of red blood cells ...
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ConferenceOptics Infobase Conference Papers · January 1, 2016
Recent Quantitative Phase Microscopy experiments have measured the refractive index of a cell nucleus to be lower than the cytoplasm. We suggest a potential error capable of corrupting these measurements. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2016
Oxygenation of hemolyzed blood was measured with multispectral multiple-scattering low coherence interferometry revealing a high correlation (r2=0.961) with gold-standard spectrophotometer measurements. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2016
Quantitative phase imaging (QPI) was implemented to image cells before and during subjugation of shear flow. Simultaneous evaluation of disorder strength and cellular stiffness showed a correlation between the two metrics. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2016
Here we present the analysis of two dimensional angle-resolved low coherence interferometry (2D a/LCI) measurements co-registered with optical coherence tomography (OCT) imaging to guide the a/LCI measurements on an esophageal cancer rat model. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2016
We assess the diagnostic capability of a/LCI in vivo for cervical cancer detection. The nuclear diameter was determined from the a/LCI scans using a Mie theory and a wavelet based hybrid analysis, and the results were compared to histopathology. ...
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Journal ArticleBiomed Opt Express · September 1, 2015
Clinical management of burn injuries depends upon an accurate assessment of the depth of the wound. Current diagnostic methods rely primarily on subjective visual inspection, which can produce variable results. In this study, spectroscopic optical coherenc ...
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ConferenceConference on Lasers and Electro Optics Europe Technical Digest · August 10, 2015
Interferometric imaging offers many advantages for biomedical applications such as optical sectioning/depth resolution. Inclusion of molecular contrast information improves utility but requires additional efforts to either isolate spectroscopic information ...
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Journal ArticleJournal of biomedical optics · August 2015
We present a dual-modality system for both structural and molecular cell imaging based on coregistered quantitative phase imaging (QPI) and photoacoustic microscopy (PAM). The QPI system was based on off-axis holography, whereas the PAM system comprised a ...
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Journal ArticleBiomed Opt Express · August 1, 2015
We evaluate a new hybrid algorithm for determining nuclear morphology using angle-resolved low coherence interferometry (a/LCI) measurements in ex vivo cervical tissue. The algorithm combines Mie theory based and continuous wavelet transform inverse light ...
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Journal ArticleBiomedical optics express · June 2015
We report the development of a combined confocal Raman spectroscopy (CRS) and optical coherence tomography (OCT) instrument (CRS-OCT) capable of measuring analytes in targeted biological tissues with sub-100-micron spatial resolution. The OCT subsystem was ...
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Journal ArticleBiomedical optics express · June 2015
Digital holography offers a unique method for studying microscopic objects using quantitative measurements of the optical phase delays of transmitted light. The optical phase may be integrated across the object to produce an optical volume measurement, a p ...
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Journal ArticlePhys Med Biol · May 21, 2015
In the past decade, several functional extensions of optical coherence tomography (OCT) have emerged, and this review highlights key advances in instrumentation, theoretical analysis, signal processing and clinical application of these extensions. We revie ...
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ConferenceBio Optics Design and Application Boda 2015 · April 6, 2015
Depth resolved spectra obtained from spectroscopic optical coherence tomography (SOCT) are used to evaluate burn injuries in vivo in a mouse model. Spectral differences between different burn severities are quantified by a power-law fitting model. ...
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ConferenceOptical Molecular Probes Imaging and Drug Delivery Omp 2015 · April 6, 2015
We report the development of a combined Raman spectroscopy and optical coherence tomography instrument. The instrument was used to accurately measure physiologically-relevant concentrations of microbicide drugs in ex vivo tissue samples. ...
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ConferenceNovel Techniques in Microscopy NTM 2015 · April 6, 2015
We present a platform for detecting cellular deformations from mechanical stimuli. Rapid quantitative phase imaging was used to analyze changes in the optical path length of skin cancer cells during mechanical displacement. ...
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Chapter · January 1, 2015
Elastically scattered light contains information about the scattering medium with which it has interacted. The elastic scattering process can be interpreted as a change in the momentum of light due to its interaction with a scattering object. By analyzing ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · December 2014
We examine the noise properties of supercontinuum light sources when used in low-coherence interferometry applications. The first application is a multiple-scattering low-coherence interferometry (ms2/LCI) system, where high power and long image acquisitio ...
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Journal ArticleOpt Lett · October 1, 2014
Spectroscopic analysis of biological tissues can provide insight into changes in structure and function due to disease or injury. Depth-resolved spectroscopic measurements can be implemented for tissue imaging using optical coherence tomography (OCT). Here ...
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Journal ArticleBiomedical optics express · October 2014
We present a fast approach for size determination of spherical scatterers using the continuous wavelet transform of the angular light scattering profile to address the computational limitations of previously developed sizing techniques. The potential accur ...
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Journal ArticleBiomedical optics express · August 2014
We present a fast, wide-field holography system for detecting photothermally excited gold nanospheres with combined quantitative phase imaging. An interferometric photothermal optical lock-in approach (POLI) is shown to improve SNR for detecting nanopartic ...
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Journal ArticleOptics letters · April 2014
We have developed a modality for quantitative phase imaging within spectral domain optical coherence tomography based on using an off-axis reference beam. By tilting the propagation of the reference beam relative to that of the sample beam, a spatially var ...
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Journal ArticlePloS one · January 2014
We have developed a quantitative imaging refractometry technique, based on holographic phase microscopy, as a tool for investigating microscopic structural changes in water-soluble polymeric materials. Here we apply the approach to analyze the structural d ...
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Journal ArticleJournal of biomedical optics · January 2014
Traditional slit-based spectrometers have an inherent trade-off between spectral resolution and throughput that can limit their performance when measuring diffuse sources such as light returned from highly scattering biological tissue. Recently, multieleme ...
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Journal ArticleOptica · January 1, 2014
Scattering limits the penetration depth of most optical imaging techniques. Efforts to overcome this limitation often require complex optical or computational schemes. We have developed a new method of assessing tissue properties based on spectroscopic ana ...
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Journal ArticleLecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics · January 1, 2014Full textCite
Journal ArticleApplied optics · December 2013
We have implemented multispectral multiple scattering low coherence interferometry (ms2/LCI) with Fourier domain data collection. The ms2/LCI system is designed to localize features with spectroscopic contrast with millimeter resolution up to 1 cm deep in ...
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Journal ArticleBio Optics Design and Application Boda 2013 · November 18, 2013
We have developed phantoms for use with two-dimensional angle-resolved lowcoherence interferometry. Here we demonstrate standardized multi-scale structural information for light scattering measurements. Optics in the Life Sciences Congress Technical Digest ...
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Journal ArticlePloS one · January 2013
We present a novel approach for measuring topical microbicide gel dilution using optical imaging. The approach compares gel thickness measurements from fluorimetry and multiplexed low coherence interferometry in order to calculate dilution of a gel. As a m ...
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Journal ArticleBiomed Opt Express · 2013
Effective treatment of patients with malignant brain tumors requires surgical resection of a high percentage of the bulk tumor. Surgeons require a method that enables delineation of tumor margins, which are not visually distinct by eye. In this study, the ...
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Journal ArticleOptical Molecular Probes Imaging and Drug Delivery Omp 2013 · January 1, 2013
The enhanced scattering of gold nanorods in the near-infrared regime provides excellent contrast for imaging within biological tissues. This study demonstrates the capability of anti-EGFR nanorods to distinguish xenograft glioblastomas from healthy murine ...
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Journal ArticleBiomedical optics express · January 2013
Angle-resolved low coherence interferometry (a/LCI) is an approach for assessing tissue structure based on light scattering data. Recent advances in a/LCI have extended the analysis to study scattering distributions in two dimensions. In order to provide s ...
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Journal ArticleStudies in health technology and informatics · January 2013
The study of intact, living cells using non-invasive optical spectroscopic methods offers the opportunity to assess cellular structure and organization in a way that is not possible with commonly used cell biology imaging techniques. We have developed a no ...
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Chapter · January 1, 2013
Optical coherence tomography (OCT) is a cross-sectional high-resolution optical imaging modality that operates under the principles of low coherence interferometry (LCI) to enable optical sectioning, or depth resolution, within a biological sample [1]. OCT ...
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Journal ArticleMethods in molecular biology (Clifton, N.J.) · January 2013
Optical coherence tomography (OCT) is a three-dimensional optical imaging technique that has been successfully implemented in ophthalmology for imaging the human retina, and in studying animal models of disease. OCT can nondestructively visualize structura ...
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Journal ArticleBiomedical optics express · January 2013
Noble metal nanoparticles exhibit enhanced scattering and absorption at specific wavelengths due to a localized surface plamson resonance. This unique property can be exploited to enable the use of plasmonic nanoparticles as contrast agents in optical imag ...
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Journal Article2012 Conference on Lasers and Electro Optics CLEO 2012 · December 6, 2012
We have developed multiple spectroscopic coherence imaging methods to assess pre-cancerous states by isolating scattering signatures from specific tissue locations. We describe the basis, validation and development of the approaches and recent clinical res ...
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Journal Article2012 Conference on Lasers and Electro Optics CLEO 2012 · December 6, 2012
We demonstrate simultaneous detection of two nanoparticle species using phase-sensitive optical coherence tomography with photothermal excitation at two wavelengths matched to the distinct absorption peaks of the nanoparticles. To minimize bulk heating of ...
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Journal ArticleCLEO: Applications and Technology, CLEO_AT 2012 · December 1, 2012
We demonstrate simultaneous detection of two nanoparticle species using phasesensitive optical coherence tomography with photothermal excitation at two wavelengths matched to the distinct absorption peaks of the nanoparticles. To minimize bulk heating of t ...
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Journal ArticleOptics Infobase Conference Papers · December 1, 2012
We demonstrate simultaneous detection of two nanoparticle species using phasesensitive optical coherence tomography with photothermal excitation at two wavelengths matched to the distinct absorption peaks of the nanoparticles. To minimize bulk heating of t ...
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Journal ArticleJournal of biomedical optics · November 2012
ABSTRACT. We used a probe-based dual-modality optical imaging instrument to measure in vivo coating thickness distributions of a gel distributed along the vaginal lumen, in a clinical study. The gel was a surrogate for one delivering an anti-HIV topical mi ...
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Journal ArticleBiomedical optics express · October 2012
We apply phase-sensitive optical coherence tomography to image multiple nanoparticle species with two excitation wavelengths matched to their distinct absorption peaks. Using different modulation frequencies, multiple species collocated within the sample c ...
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Journal ArticleBiomedical optics express · August 2012
We have recently developed a novel dual window scheme for processing spectroscopic OCT images to provide spatially resolved true color imaging of chromophores in scattering samples. Here we apply this method to measure the extinction spectra of plasmonic n ...
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Journal ArticleIEEE Journal on Selected Topics in Quantum Electronics · June 20, 2012
With recent results demonstrating imaging using low coherence interferometry to detect multiply scattered light, signal attenuation and imaging resolution remains to be an open question. To address this, we present detailed modeling results of light propag ...
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Journal ArticleBiomedical optics express · May 2012
Quantitative phase spectroscopy is presented as a novel method of measuring the wavelength-dependent refractive index of microscopic volumes. Light from a broadband source is filtered to an ~5 nm bandwidth and rapidly tuned across the visible spectrum in 1 ...
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ConferenceProgress in Biomedical Optics and Imaging Proceedings of SPIE · April 16, 2012
We have applied wide-field digital interferometric techniques to quantitatively image sickle red blood cells (RBCs) [1] in a noncontact label-free manner, and measure the nanometer-scale fluctuations in their thickness as an indication of their stiffness. ...
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Journal ArticleMethods (San Diego, Calif.) · February 2012
Noble metal nanoparticles hold great potential as optical contrast agents due to a unique feature, known as the plasmon resonance, which produces enhanced scattering and absorption at specific frequencies. The plasmon resonance also provides a spectral tun ...
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Journal ArticleExpert review of gastroenterology & hepatology · February 2012
Angle-resolved low-coherence interferometry (a/LCI) is an optical biopsy technique that measures scattered light from tissue to determine nuclear size with submicron-level accuracy. The a/LCI probe can be deployed through the accessory channel of a standar ...
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Journal ArticleBiomedical Optics Biomed 2012 · January 1, 2012
We present live cell imaging using spectral-domain differential interference contrast microscopy, a novel technique for high-resolution, quantitative measurement of optical pathlength gradients. Imaging and dynamic monitoring of live neurons and cardiomyoc ...
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Journal ArticleCLEO Applications and Technology CLEO at 2012 · January 1, 2012
We demonstrate simultaneous detection of two nanoparticle species using phasesensitive optical coherence tomography with photothermal excitation at two wavelengths matched to the distinct absorption peaks of the nanoparticles. To minimize bulk heating of t ...
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Journal ArticleCLEO Applications and Technology CLEO at 2012 · January 1, 2012
We have developed multiple spectroscopic coherence imaging methods to assess pre-cancerous states by isolating scattering signatures from specific tissue locations. We describe the basis, validation and development of the approaches and recent clinical res ...
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Journal ArticleAnnual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference · January 2012
Conventional spectrometers are limited in the amount of light they accept because of the requirement for narrow input apertures. A trade-off must generally be made between spectral resolution and input aperture width. This is especially a problem for perfo ...
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Journal ArticleJournal of biomedical optics · December 2011
Quantitative phase microscopy is applied to image temporal changes in the refractive index (RI) distributions of solutions created by microbicidal films undergoing hydration. We present a novel method of using an engineered polydimethylsiloxane structure a ...
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Journal ArticleNat Photonics · December 1, 2011
Molecular imaging holds a pivotal role in medicine due to its ability to provide invaluable insight into disease mechanisms at molecular and cellular levels. To this end, various techniques have been developed for molecular imaging, each with its own advan ...
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Journal ArticleOptics letters · December 2011
Nonlinear phase dispersion spectroscopy is introduced as a means to retrieve wideband, high spectral resolution profiles of the wavelength-dependent real part of the refractive index. The method is based on detecting dispersion effects imparted to a light ...
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Journal ArticleSpringer Series in Surface Sciences · December 1, 2011
Interferometric phase measurements of wide-field images of biological cells provide a quantitative tool for cell biology, as well as for medical diagnosis and monitoring. Visualizing rapid dynamic cell phenomena by interferometric phase microscopy can be p ...
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Journal ArticleJournal of biomedical optics · November 2011
This work presents simultaneous imaging and detection of three different cell receptors using three types of plasmonic nanoparticles (NPs). The size, shape, and composition-dependent scattering profiles of these NPs allow for a system of multiple distinct ...
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Journal ArticleACS nano · November 2011
The dimerization of receptors on the cell membrane is an important step in the activation of cell signaling pathways. Several methods exist for observing receptor dimerization, including coimmunoprecipitation, chemical cross-linking, and fluorescence reson ...
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Journal ArticleJ Biomed Opt · October 2011
Angle-resolved low coherence interferometry (a/LCI) is an optical biopsy technique that allows for depth-resolved, label-free measurement of the average size and optical density of cell nuclei in epithelial tissue to assess the tissue health. a/LCI has pre ...
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Journal ArticleBiomedical optics express · October 2011
We present a multiplexed, Fourier-domain low coherence interferometry (mLCI) instrument for in vivo measurement of intravaginal microbicide gel coating thickness distribution over the surface of the vaginal epithelium. The mLCI instrument uses multiple del ...
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Journal ArticleIntegrative biology : quantitative biosciences from nano to macro · August 2011
We hypothesised that global structural changes in stem cells would manifest with differentiation, and that these changes would be observable with light scattering microscopy. Analysed with a fractal dimension formalism, we observed significant structural c ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · May 12, 2011
Interferometric based imaging has a number of advantages over direct detection of photons, including very high time resolution, shot noise limited sensitivity, and reasonable cost. In spite of these advantages, diffuse optical techniques have almost exclus ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · May 2, 2011
The effectiveness of microbicidal gels, topical products developed to prevent infection by sexually transmitted diseases including HIV/AIDS, is governed by extent of gel coverage, pharmacokinetics of active pharmaceutical ingredients (APIs), and integrity ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · April 29, 2011
Whole cell imaging is a novel technique using which the time-dependent quantitative phase profiles of live unstained biological cells are analyzed numerically to learn on the cell functionally. Dynamic phase profiles of the sample are first acquired by wid ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · April 29, 2011
This work presents simultaneous imaging and detection of three types of cell receptors using three types of plasmonic nanoparticles. The size, shape, and composition-dependent scattering profiles of these particles allow for a system of multiple distinct m ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · March 31, 2011
Angle-resolved scattering measurements have shown promise as a method of detecting neoplasia and analyzing cellular structure. Recently we have developed new systems for interferometric measurement of two-dimensional, depth resolved scattered fields with e ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · March 31, 2011
We present Fourier domain low coherence interferometry (fLCI) applied to the detection of preneoplastic changes in the colon using the ex-vivo azoxymethane (AOM) rat carcinogenesis model. fLCI measures depth resolved spectral oscillations, also known as lo ...
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Journal ArticleJ Biomed Opt · March 2011
We have applied wide-field digital interferometry (WFDI) to examine the morphology and dynamics of live red blood cells (RBCs) from individuals who suffer from sickle cell anemia (SCA), a genetic disorder that affects the structure and mechanical propertie ...
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Journal ArticleOptics letters · March 2011
We propose the use of polarization mapping as a tool to better separate the effects of plasmonic coupling from the local refractive index for molecular imaging and biosensing using gold nanoparticles. Polarization mapping allows identification of the ortho ...
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Journal ArticleOptics letters · February 2011
We present a fiber-optic low-coherence imaging technique, termed spectral-domain differential interference contrast microscopy (SD-DIC), for quantitative DIC imaging of both reflective surfaces and transparent biological specimens. SD-DIC combines the comm ...
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Journal ArticleOptics express · February 2011
We present an imaging system based on low coherence interferometric detection of multiply scattered light for extended depth imaging into highly scattering media. By incorporating angle-resolved detection, coherence imaging with multiply scattered photons ...
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Journal ArticleOptics InfoBase Conference Papers · January 1, 2011
A clinical optical imaging probe incorporating simultaneous fluorescence and low coherence interferometry (LCI) imaging optics was developed. A clinical study was performed to compare LCI and fluorimetry in measuring intravaginal microbicide gel coating th ...
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Journal ArticleOptics Infobase Conference Papers · January 1, 2011
A clinical optical imaging probe incorporating simultaneous fluorescence and low coherence interferometry (LCI) imaging optics was developed. A clinical study was performed to compare LCI and fluorimetry in measuring intravaginal microbicide gel coating th ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2011
Live biological cells are three-dimensional microscopic objects that constantly adjust their sizes, shapes and other biophysical features. Wide-field digital interferometry (WFDI) is a holographic technique that is able to record the complex wavefront of t ...
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ConferenceOptics InfoBase Conference Papers · January 1, 2011
Molecular imaging using Photothermal Optical Coherence Tomography (OCT) was demonstrated with antibody-conjugated gold nanoparticles in phantoms and three-dimensional tissue constructs. Cells over-expressing the epidermal growth factor receptor (EGFR) were ...
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Journal ArticleOptics InfoBase Conference Papers · 2011
A clinical optical imaging probe incorporating simultaneous fluorescence and low coherence interferometry (LCI) imaging optics was developed. A clinical study was performed to compare LCI and fluorimetry in measuring intravaginal microbicide gel coating th ...
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ConferenceOptics Infobase Conference Papers · January 1, 2011
Molecular imaging using Photothermal Optical Coherence Tomography (OCT) was demonstrated with antibody-conjugated gold nanoparticles in phantoms and three-dimensional tissue constructs. Cells over-expressing the epidermal growth factor receptor (EGFR) were ...
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Journal ArticleCytometry A · January 2011
Fluorescence-based flow cytometry measures multiple cellular characteristics, including levels of receptor expression, by assessing the fluorescence intensity from a population of cells whose cell surface receptors are bound by a fluorescently labeled anti ...
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Journal ArticleAnalytical cellular pathology (Amsterdam) · January 2011
The study of intact, living cells using non-invasive optical spectroscopic methods offers the opportunity to assess cellular structure and organization in a way that is not possible with commonly used cell biology imaging techniques. We have developed a no ...
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Journal ArticleJournal of biomedical optics · January 2011
We present a novel Fourier-domain angle-resolved low-coherence interferometry (a /LCI) fiber probe designed for in vivo clinical application in gastrointestinal endoscopy. The a/LCI technique measures the depth-resolved angular scattering distribution to d ...
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Journal ArticleGastroenterology · January 2011
Background & aimsPatients with Barrett's esophagus (BE) show increased risk of developing esophageal adenocarcinoma and are routinely examined using upper endoscopy with biopsy to detect neoplastic changes. Angle-resolved low coherence interferome ...
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Journal ArticleJournal of carcinogenesis · January 2011
This review covers the development of angle-resolved low coherence interferometry (a/LCI) from initial development through clinical application. In the first applications, the approach used a time-domain interferometry scheme and was validated using animal ...
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Journal ArticleOptics InfoBase Conference Papers · December 1, 2010
This tutorial reviews coherence imaging approaches for biomedical applications. Subjects will include digital holography and optical coherence tomography modalities with an emphasis on basis of image formation, functional extensions and biological applicat ...
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Journal ArticleOptics letters · September 2010
We present an analytical method that yields the real and imaginary parts of the refractive index (RI) from low-coherence interferometry measurements, leading to the separation of the scattering and absorption coefficients of turbid samples. The imaginary R ...
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Journal ArticleBiomedical optics express · August 2010
We apply wide-field interferometric microscopy techniques to acquire quantitative phase profiles of ventricular cardiomyocytes in vitro during their rapid contraction with high temporal and spatial resolution. The whole-cell phase profiles are analyzed to ...
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Journal ArticleBiomedical optics express · August 2010
Fourier domain low coherence interferometry (fLCI) is an emerging optical technique used to quantitatively assess cell nuclear morphology in tissue as a means of detecting early cancer development. In this work, we use the azoxymethane rat carcinogenesis m ...
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Journal ArticleOptics letters · August 2010
We present a quantitative phase microscopy method that uses a Bayer mosaic color camera to simultaneously acquire off-axis interferograms in transmission mode at two distinct wavelengths. Wrapped phase information is processed using a two-wavelength algori ...
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Journal ArticleOptics express · July 5, 2010
We demonstrate accurate determination of the size and shape of spherical and spheroidal scatterers through inverse analysis of two-dimensional solid-angle and depth resolved backscattered light intensities. Intensity of scattered light is measured over a w ...
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Journal ArticleOptics express · July 2010
We demonstrate accurate determination of the size and shape of spherical and spheroidal scatterers through inverse analysis of two-dimensional solid-angle and depth resolved backscattered light intensities. Intensity of scattered light is measured over a w ...
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Journal ArticleIEEE Journal on Selected Topics in Quantum Electronics · July 1, 2010
Biomedical applications of light scattering have traditionally relied on Mie theory as a theoretical basis for analyzing experimental measurements. While this approach is computationally accessible, the use of Mie theory cannot always account for the spher ...
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Journal Article · May 20, 2010
We apply a wide-field quantitative phase microscopy technique based on parallel two-step phase-shifting on-axis interferometry to visualize live biological cells and microorganism dynamics. The parallel on-axis holographic approach is more efficient with c ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · May 7, 2010
Light scattering spectroscopy (LSS) and Fourier domain low coherence interferometry (fLCI) are used in combination with the dual window method (DW) to measure scattering features from a thick turbid sample. By processing with the DW method, the trade off t ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · May 7, 2010
Improved methods for detecting dysplasia, or pre-cancerous growth are a current clinical need, particularly in the esophagus. The currently accepted method of random biopsy and histological analysis provides only a limited examination of tissue in question ...
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Journal ArticleJournal of biomedical optics · May 2010
We introduce a new interferometric setup for single-exposure wide-field holographic phase imaging of highly dynamic biological samples. In this setup, the interferometric signal originates from a specially designed reflective interferometric chamber (InCh) ...
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Journal ArticleApplied optics · May 2010
We apply a wide-field quantitative phase microscopy technique based on parallel two-step phase-shifting on-axis interferometry to visualize live biological cells and microorganism dynamics. The parallel on-axis holographic approach is more efficient with c ...
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Journal ArticleOptics letters · May 2010
We present a fiber-optic interferometric system for measuring depth-resolved scattering in two angular dimensions using Fourier-domain low-coherence interferometry. The system is a unique hybrid of the Michelson and Sagnac interferometer topologies. The co ...
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Journal ArticleSoft matter · April 2010
Cells sense cues in their surrounding microenvironment. These cues are converted into intracellular signals and transduced to the nucleus in order for the cell to respond and adapt its function. Within the nucleus, structural changes occur that ultimately ...
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Journal ArticleOptics letters · February 2010
We present measurements of morphological features in a thick turbid sample using light-scattering spectroscopy (LSS) and Fourier-domain low-coherence interferometry (fLCI) by processing with the dual-window (DW) method. A parallel frequency domain optical ...
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ConferenceOptics Infobase Conference Papers · January 1, 2010
This tutorial reviews coherence imaging approaches for biomedical applications. Subjects will include digital holography and optical coherence tomography modalities with an emphasis on basis of image formation, functional extensions and biological applicat ...
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Journal ArticleJournal of biomedical optics · January 2010
We experimentally implement label-free phase microscopy using wide-field digital interferometry (WFDI) techniques to retrieve quantitative volumetric data of articular chondrocyte dynamics. Using the scanless interferometric system, we visualize chondrocyt ...
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Journal ArticleAip Conference Proceedings · January 1, 2010
Interferometric phase microscopy of biological cell dynamics has the potential to provide a label-free quantitative tool for cell biology, as well as for medical diagnosis and monitoring. The current state of the art of this field, the open questions, and ...
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Journal ArticleOptics Infobase Conference Papers · December 1, 2009
We introduce a new fast and accurate method for dynamic quantitative phase imaging of biological cells. The method enables imaging of sub-millisecond dynamic biological phenomena with sub-nanometer temporal stability. Initial experimental results are given ...
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Journal ArticleLaser and Photonics Reviews · November 23, 2009
Noble metal nanoparticles exhibit a plasmonic resonance that provides them with unique optical properties. The sensitivity of the plasmonic resonance to the surrounding dielectric environment has lead to the development of metal nanoparticles as the basis ...
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Journal Article2009 Conference on Lasers and Electro Optics and 2009 Conference on Quantum Electronics and Laser Science Conference CLEO QELS 2009 · November 16, 2009
We introduce a new fast and accurate method for dynamic quantitative phase imaging of biological cells. The method enables imaging of sub-millisecond dynamic biological phenomena with sub-nanometer temporal stability. Initial experimental results are given ...
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Journal ArticleJournal of biomedical optics · November 2009
We have developed a novel dual-window approach for spectroscopic optical coherence tomography (OCT) measurements and applied it to probe nuclear morphology in tissue samples drawn from the hamster cheek pouch carcinogenesis model. The dual-window approach ...
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Journal ArticleOptics letters · October 2009
We present a fiber-optic probe for Fourier-domain angle-resolved low coherence interferometry for the determination of depth-resolved scatterer size. The probe employs a scanning single-mode fiber to collect the angular scattering distribution of the sampl ...
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Journal ArticleOptics express · August 2009
We present a phase-shifting interferometric technique for imaging live biological cells in growth media, while optimizing spatial resolution and enabling potential real-time measurement capabilities. The technique uses slightly-off-axis interferometry whic ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · June 12, 2009
Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor (HER2) contribute to the regulation of cell proliferation, and when jointly over-expressed are associated with several types of cancer. The ability to monitor both receptors ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · June 12, 2009
Methods for the optimization of a/LCI for clinical use are presented. First, the use of the T-matrix light scattering model to simulate scattering from spheroidal particles is presented as a more appropriate simulation of cell nuclei scattering than the pr ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · June 12, 2009
Fourier Domain Low Coherence Interferometry (fLCI) is an optical technique that recovers depth-resolved spectroscopic information about scatterers. The current fLCI system utilizes a white light Xe arc lamp source, a 4-f interferometer, and an imaging spec ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · June 12, 2009
Inverse light scattering methods have been applied by several groups as a means to probe cellular structure in both clinical and scientific applications with sub-wavelength accuracy. These methods determine the geometric properties of tissue scatterers bas ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · June 8, 2009
Microbicide gels are topical products that have recently been developed to combat sexually transmitted diseases including HIV/AIDS. The extent of gel coverage, thickness, and structure are crucial factors in gel effectiveness. It is necessary to be able to ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · May 5, 2009
The generation of spectroscopic optical coherence tomography (SOCT) signals suffers from an inherent trade off between spatial and spectral resolution. Here, we present a dual window (DW) method that uses two Gaussian windows to simultaneously obtain high ...
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Journal ArticleACS nano · April 2009
We present the development of an analytical model that can be used for the rational design of a biosensor based on shifts in the local surface plasmon resonance (LSPR) of individual gold nanoparticles. The model relates the peak wavelength of light scatter ...
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Journal ArticleApplied optics · April 2009
We present a Fourier-domain, multiplexed low coherence interferometry (LCI) instrument designed for application to intravaginal measurement of microbicidal gel distribution. Microbicide gels are topical products developed to combat sexually transmitted dis ...
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Journal ArticleApplied optics · April 2009
Inverse light scattering analysis (ILSA) seeks to associate measured scattering properties with the most probable theoretical scattering distribution, making it a useful tool for assessing structure in biological materials. The accuracy of ILSA depends on ...
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Journal ArticleOptics express · April 2009
Current methods for analysis of spectroscopic optical coherence tomography (SOCT) signals suffer from an inherent tradeoff between time (depth) and frequency (wavelength) resolution. Here, we present a dual window (DW) method for reconstructing time freque ...
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Journal ArticleAJR Am J Roentgenol · April 2009
OBJECTIVE: The goal of this study was to assess whether immunolabeled nanoparticle biomarkers are comparable to fluorescent marker imaging in measuring epidermal growth factor receptor (EGFR) expression. MATERIALS AND METHODS: EGFR expression was quantifie ...
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Journal ArticleGastrointestinal endoscopy clinics of North America · April 2009
Reflectance spectroscopy is an emerging technology which provides rapid and safe evaluation of tissue for dysplasia and ischemia. The probe-based devices can be passed through most endoscopes. Current applications include detection of dysplasia in Barrett' ...
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Journal ArticleOptics letters · March 2009
We introduce and experimentally demonstrate a fast and accurate method for quantitative imaging of the dynamics of live biological cells. Using a dual-channel interferometric setup, two phase-shifted interferograms of nearly transparent biological samples ...
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Journal ArticleAnnals of biomedical engineering · March 2009
In the absence of active volume regulation processes, cell volume is inversely proportional to osmolarity, as predicted by the Boyle Van't Hoff relation. In this study, we tested the hypothesis that nuclear volume has a similar relationship with extracellu ...
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Journal ArticleCancer research · February 2009
We present a light scattering study using angle-resolved low coherence interferometry (a/LCI) to assess nuclear morphology and subcellular structure within MCF-7 cells at several time points after treatment with chemotherapeutic agents. Although the nuclea ...
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Journal ArticleOptics letters · November 2008
We demonstrate an inverse light-scattering analysis procedure based on using the T-matrix method as a light-scattering model. We measure light scattered by in vitro cell monolayers using angle-resolved low-coherence interferometry (a/LCI) and compare the d ...
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Journal ArticleNano letters · October 2008
Molecular imaging is a powerful tool for investigating disease processes and potential therapies in both in vivo and in vitro systems. However, high resolution molecular imaging has been limited to relatively shallow penetration depths that can be accessed ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · August 2008
Inverse light scattering analysis seeks to associate measured scattering properties with the most probable theoretical scattering distribution. Although Mie theory is a spherical scattering model, it has been used successfully for discerning the geometry o ...
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Journal ArticleOptics letters · June 2008
We use a parallel frequency-domain optical coherence tomography (FDOCT) system to generate a scatter-mode image of the hamster cheek pouch epithelium. To our knowledge, this is the first optical coherence tomography (OCT) image of a biological sample obtai ...
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Journal ArticleBiophysical journal · June 2008
Accurate measurements of nuclear deformation, i.e., structural changes of the nucleus in response to environmental stimuli, are important for signal transduction studies. Traditionally, these measurements require labeling and imaging, and then nuclear meas ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · April 21, 2008
A well-established method of assessing structure is inverse light scattering analysis. With inverse light scattering analysis, the measured scattering properties of a scatterer(s) are associated with the most probable scattering distribution predicted by a ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · April 21, 2008
Fourier Domain Low Coherence Interferometry (fLCI) is a promising technique which combines the depth resolution of low coherence interferometry with the sensitivity of light scattering spectroscopy for probing the health of epithelial tissue layers. Our ne ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · April 21, 2008
Improved methods for detecting dysplasia, or pre-cancerous growth are a current clinical need, particularly in the esophagus. The currently accepted method of random biopsy and histological analysis provides only a limited examination of tissue in question ...
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Journal ArticleAnalytical chemistry · February 2008
We report the use of individual gold nanorods as plasmonic transducers to detect the binding of streptavidin to individual biotin-conjugated nanorods in real time on a surface. Label-free detection at the single-nanorod level was performed by tracking the ...
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Journal ArticleOptics Infobase Conference Papers · January 1, 2008
Asynchronous digital holography has been developed for quantitative phase measurements, and will be extended to multi-wavelength phase unwrapping and 3D tomographic reconstruction. Results acquired from standard samples and also live cell samples will be p ...
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Journal ArticleOptics Infobase Conference Papers · January 1, 2008
Asynchronous digital holography has been developed for quantitative phase measurements, and will be extended to multi-wavelength phase unwrapping and 3D tomographic reconstruction. Results acquired from standard samples and also live cell samples will be p ...
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ConferenceBiomedical Optics Biomed 2008 · January 1, 2008
Asynchronous digital holography has been developed for quantitative phase measurements, and will be extended to multi-wavelength phase unwrapping and 3D tomographic reconstruction. Results acquired from standard samples and also live cell samples will be p ...
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Journal ArticleJournal of biomedical optics · January 2008
We present a study using plasmonic nanoparticles (NPs) to image epidermal growth factor receptor (EGFR) in live cells. Through detailed analysis of the NP scattering spectra, we determine the intracellular refractive index (RI) within attoliter volumes ins ...
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Journal ArticleDisease markers · January 2008
Light scattering spectroscopy measurements can be used to determine the structure of tissue samples. Through refined data acquisition and signal processing techniques, quantitative nuclear morphology measurements may be obtained from light scattering data. ...
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Journal ArticleIEEE Journal on Selected Topics in Quantum Electronics · January 1, 2008
The combination of low-coherence interferometry with angle-resolved light scattering measurements has been shown to be a powerful method for determining the structure of cell nuclei within intact tissue samples. The nuclear morphology data have been used a ...
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Journal ArticleBiomedical Optics Biomed 2008 · January 1, 2008
Darkfield microspectroscopy enables detailed studies of the plasmonic features of noble metal nanoparticles. Shifts of the plasmon resonance of individual nanoparticles can be exploited for sensing applications or to achieve molecular imaging using targete ...
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Journal ArticleBiomedical Optics Biomed 2008 · January 1, 2008
We present a novel hyperspectral darkfield microscopy scheme that utilizes an epiillumination light train for improved characterization of the sensing capacity of noble metal nanoparticles. Validation experiments are presented to characterize the new syste ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · August 31, 2007
Fourier domain low coherence interferometry (fLCI) is an optical technique which combines the depth resolution of low coherence interferometry with the sensitivity of light scattering spectroscopy. The fLCI system uses a white light source in a modified Mi ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · August 31, 2007
Improved methods for detecting dysplasia, or pre-cancerous growth, are a current clinical need. Random biopsy and subsequent diagnosis through histological analysis is the current gold standard in endoscopic surveillance for dysplasia. However, this approa ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · August 2007
Traditional analysis of spectroscopic optical coherence tomography (SOCT) signals is limited by an uncertainty relationship between time (depth) and frequency (wavelength). The use of a bilinear time-frequency distribution for analysis, such as those that ...
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Journal ArticleOptics letters · May 2007
We present here the results of a numerical study on light scattering from nonspherical particles with relevance to detecting precancerous states in epithelial tissues. In previous studies of epithelial cell nuclei, the experimental light scattering data ha ...
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Journal ArticleApplied optics · April 2007
Angle-resolved low-coherence interferometry (a/LCI) enables us to make depth-resolved measurements of scattered light that can be used to recover subsurface structural information such as the size of cell nuclei. Endoscopic frequency-domain a/LCI (fa/LCI) ...
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Journal ArticleApplied optics · April 2007
One goal of recent research on plasmonic nanoparticle-based sensors is maximizing nanoparticle sensitivity or shift of resonance peak wavelength per refractive index change. Equally important is a measurement system's peak location uncertainty or shift res ...
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Journal ArticleGastrointest Endosc · March 2007
BACKGROUND: Monitoring of patients with Barrett's esophagus (BE) for dysplasia, currently done by systematic biopsy, can be improved through increasing the proportion of at-risk tissue examined. OBJECTIVE: Optical biopsy techniques, which do not remove the ...
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Journal ArticleOptics express · March 2007
We demonstrate a new method of measuring quantitative phase in imaging of biological materials. This method, asynchronous digital holography, employs knowledge of a moving fringe created by acousto-optic modulators to execute phase-shifting interferometry ...
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Journal ArticleCancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · February 2007
Optical spectroscopy was used to evaluate the transformation of nuclear morphology associated with intraepithelial neoplasia in an animal model of carcinogenesis. In this pilot study, we have assessed the capability of angle-resolved low-coherence interfer ...
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Journal ArticleCancer Biomark · 2007
The concept of intraepithelial neoplasm (IEN) as a near-obligate precursor of cancers has generated opportunities to examine drug or device intervention strategies that may reverse or retard the sometimes lengthy process of carcinogenesis. Chemopreventive ...
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Journal ArticlePhysical review letters · September 2006
Light scattered from biological tissues can exhibit an inverse power law spectral component. We develop a model based on the Born approximation and von Karman (self-affine) spatial correlation of submicron tissue refractive index to account for this. The m ...
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Journal ArticleOptics express · July 2006
Existing darkfield illumination schemes are incompatible with many types of samples and/or procedures. We present a darkfield epi-illumination scheme which addresses these incompatibilities by providing illumination through the imaging objective. We valida ...
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Journal ArticleJournal of biomedical optics · May 2006
Angle-resolved low coherence interferometry (a/LCI) enables depth-resolved measurements of scattered light that can be used to recover subsurface structural information, such as the size of cell nuclei. Measurements of nuclear morphology, however, can be c ...
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Journal ArticleJournal of biomedical optics · March 2006
Spectral-domain low-coherence interferometry (LCI) was used to measure the thickness of microbicidal gels applied to a cylindrical calibration test socket. Microbicides are topical formulations containing active ingredients targeted to inhibit specific pat ...
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Journal ArticleOptics letters · March 2006
We present a novel endoscopic fiber bundle probe incorporated in a Fourier-domain angle-resolved low coherence interferometry system for the measurement of depth-resolved angular scattering distributions to permit the determination of scatterer size via el ...
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Journal ArticleOptics Infobase Conference Papers · January 1, 2006
We present a system for the rapid characterization of nanoparticles for biosensors, providing concurrent atomic force microscopy and scattering spectra of individual nanoparticles and simultaneous spectra from various nanostructures created by electron bea ...
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Journal ArticleOptics InfoBase Conference Papers · January 1, 2006
Endoscopic Fourier-domain angle-resolved low coherence interferometry has been developed for depth resolved light scattering spectroscopy. System capabilities are demonstrated by determining the nuclei size in tissue phantoms, cell cultures and ex vivo hum ...
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Journal ArticleOptics InfoBase Conference Papers · January 1, 2006
Existing darkfield illumination schemes are incompatible with many types of samples and/or procedures. We present a darkfield scheme which addresses these incompatibilities. We then apply the scheme to evaluate nanoparticles binding cancer cells in culture ...
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Journal ArticleOptics Infobase Conference Papers · January 1, 2006
Scattering tissue phantoms are developed for assessment of promising optical precancer diagnostic technique. The tissue phantoms provide a valuable evaluation method for the low-coherence interferometry technique. Size determination results and phantom rel ...
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ConferenceOptics Infobase Conference Papers · January 1, 2006
Existing darkfield illumination schemes are incompatible with many types of samples and/or procedures. We present a darkfield scheme which addresses these incompatibilities. We then apply the scheme to evaluate nanoparticles binding cancer cells in culture ...
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ConferenceOptics Infobase Conference Papers · January 1, 2006
Endoscopic Fourier-domain angle-resolved low coherence interferometry has been developed for depth resolved light scattering spectroscopy. System capabilities are demonstrated by determining the nuclei size in tissue phantoms, cell cultures and ex vivo hum ...
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Journal ArticleJournal of biomedical optics · September 2005
Angle-resolved low-coherence interferometry (a/LCI) is used to obtain quantitative, depth-resolved nuclear morphology measurements. We compare the average diameter and texture of cell nuclei in rat esophagus epithelial tissue to grading criteria establishe ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · July 21, 2005
We have developed Fourier domain low coherence interferometry (fLCI), a novel optical interferometry method for obtaining depth-resolved spectral information, specifically for the purpose of determining the size of scatterers by measuring their elastic sca ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · July 21, 2005
We have developed a novel angle-resolved low coherence interferometry scheme for rapid measurement of depth-resolved angular scattering distributions. These measurements enable the determination of scatterer size via elastic scattering properties. The sche ...
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Journal ArticleProgress in Biomedical Optics and Imaging Proceedings of SPIE · July 21, 2005
Angle-resolved low coherence interferometry enables depth-resolved measurements of scattered light. The scattered light measurements can be used to recover structural information from sub-surface layers, such as the size of cell nuclei. Measurements of nuc ...
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Journal ArticleOptics express · June 2005
We present a new common path configuration Fourier domain low coherence interferometry (fLCI) optical system and demonstrate its capabilities by presenting results which determine the size of cell nuclei in a monolayer of T84 epithelial cells. The optical ...
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Journal ArticleApplied optics · April 2005
We present a low-cost, high-speed, retrofitted laser scanning module for microscopy. The cage-mounted system, with various available fiber-coupled sources, offers a real-time imaging alternative to costly commercial systems with capabilities for convention ...
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Journal ArticleOptics express · April 2005
We use optical darkfield micro-spectroscopy to characterize the plasmon resonance of individual silver nanoparticles in the presence of a substrate. The optical system permits multiple individual nanoparticles to be identified visually for simultaneous spe ...
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Journal ArticleApplied optics · April 2005
We analyze the performance of three imaging systems to detect near-forward scattered light interferometrically by using a Mach-Zehnder geometry. The alignment of each system is demonstrated by measurement of the heterodyne efficiency and correlation of the ...
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Journal ArticleApplied optics · March 2005
Harmonic phase-dispersion microscopy (PDM) is a new imaging technique in which contrast is provided by differences in refractive index at two harmonically related wavelengths. We report a new configuration of the harmonic phase-dispersion microscope in a M ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · February 2005
The calculation of angular light-scattering distributions is considered for low-coherence light incident on a polydisperse particle size distribution of scatterers. As low-coherence light is now commonly used in interferometry schemes when applied to biome ...
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Journal ArticleOptics Infobase Conference Papers · January 1, 2005
We present a system for the rapid characterization of nanoparticles for biosensors, providing concurrent atomic force microscopy and scattering spectra of individual nanoparticles and simultaneous spectra from various nanostructures created by electron bea ...
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Journal Article2005 Conference on Lasers and Electro Optics CLEO · January 1, 2005
We present a system for the rapid characterization of nanoparticles for biosensors, providing concurrent atomic force microscopy and scattering spectra of individual nanoparticles and simultaneous spectra from various nanostructures created by electron bea ...
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Journal ArticleOptics express · December 2004
We present a novel angle-resolved low coherence interferometry scheme for rapid measurement of depth-resolved angular scattering distributions to enable determination of scatterer size via elastic scattering properties. Depth resolution is achieved using a ...
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Journal ArticleOptics letters · October 2004
We describe a quantitative phase-imaging interferometer in which phase shifting and noise cancellation are performed by an active feedback loop using a reference laser. Depth gating via low-coherence light allows phase measurement from weakly reflecting bi ...
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ConferenceOptics Infobase Conference Papers · January 1, 2004
Angle-resolved low coherence interferometry is used to detect pre-cancerous basal epithelial cells in intact, unstained animal tissues via quantitative nuclear morphology measurements. Recent results are presented which demonstrate the ability to assess th ...
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ConferenceOptics Infobase Conference Papers · January 1, 2004
We present a low-cost, high-speed, retrofitted laser scanning module for microscopy. This fiber-coupled source, cage-mounted system offers a real-time imaging alternative to costly commercial systems and can be easily adapted for confocal and fluorescence ...
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ConferenceOptics Infobase Conference Papers · January 1, 2004
We describe results of calibration experiments using a new angle-resolved low coherence interferometry system. Light scattered from a polystyrene microsphere sample are compared with Mie Theory predictions to determine the size of the particles. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2004
Angle-resolved low coherence interferometry is used to detect pre-cancerous basal epithelial cells in intact, unstained animal tissues via quantitative nuclear morphology measurements. Recent results are presented which demonstrate the ability to assess th ...
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Journal ArticleOptics express · December 2003
We outline the process for determining the morphology of subsurface epithelial cell nuclei using depth-resolved light scattering measurements. The measurements are accomplished using a second generation angle-resolved low coherence interferometry system. T ...
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Journal ArticleTechnology in cancer research & treatment · December 2003
Reflectance and fluorescence spectroscopies have shown great promise for early detection of epithelial dysplasia. We have developed a clinical reflectance spectrofluorimeter for multimodal spectroscopic diagnosis of epithelial dysplasia. This clinical inst ...
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Journal ArticleOptics letters · July 2003
We present a novel method for obtaining depth-resolved spectra for determining scatterer size through elastic-scattering properties. Depth resolution is achieved with a white-light source in a Michelson interferometer with the mixed signal and reference fi ...
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Journal ArticleCancer research · July 2003
We present a quantitative study of the nuclear morphometry of epithelial cells in an animal model of esophageal carcinogenesis. Changes in the size and texture of cell nuclei as a result of neoplastic transformation and chemopreventive action are observed ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · April 2002
We employ a novel interferometer to measure the angular distribution of light backscattered by a turbid medium. Through comparison of the measured data with the predictions of Mie theory, we are able to determine the size of the scatterers comprising the m ...
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Journal ArticleBiophysical journal · April 2002
We measure the organization and substructure of HT29 epithelial cells in a monolayer using angle-resolved low-coherence interferometry. This new technique probes cellular structure by measuring scattered light, as in flow cytometry, but offers an advantage ...
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Journal ArticleOptics Letters · January 15, 2002
We report a highly accurate phase-based technique for measuring arbitrarily long optical distance with sub-nanometer precision. The method employs a Michelson interferometer with a pair of harmonically related light sources, one cw and the other low cohere ...
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ConferenceOptics Infobase Conference Papers · January 1, 2002
We use angular low coherence interferometry (a/LCI) to measure the size of cell nuclei and organization of smaller cell components for sub-surface layers in living tissues, demonstrating its applicability for detecting early stages of neoplasia. ...
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ConferenceOptics Infobase Conference Papers · January 1, 2002
We present an innovative technique for simultaneous measurement of the angular and spectral distributions of light backscattered by biological cells and tissues. The intensities of light scattered to different angular regions are due to scatterers of diffe ...
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ConferenceOptics Infobase Conference Papers · January 1, 2002
Diffuse reflectance spectra are analyzed using a light-diffusion-theory-based model, which assumes that tissue scattering can be simulated by Mie scattering with an inverse power-law particle size distribution. Diagnostic information related to tissue orga ...
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Journal ArticleOpt. Lett. (USA) · 2002
We report a highly accurate phase-based technique for measuring arbitrarily long optical distance with subnanometer precision. The method employs a Michelson interferometer with a pair of harmonically related light sources, one cw and the other low coheren ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2002
We report the use of a highly sensitive phase based motion measurement technique to study the correlation of cellular metabolic rate with cellular motions. The technique is based on a modified Michelson interferometer with a composite laser beam of 1550 nm ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2002
Light scattering spectroscopy (LSS) is a promising optical technique developed for quantitative characterization of tissue morphology as well as in vivo detection and diagnosis of disease such as early cancer. LSS employs a wavelength dependent component o ...
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Journal ArticleIEEE Journal on Selected Topics in Quantum Electronics · November 1, 2001
We present a novel instrument for imaging the angular distributions of light backscattered by biological cells and tissues. The intensities in different regions of the image are due to scatterers of different sizes. We exploit this to study scattering from ...
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Journal ArticleConference on Lasers and Electro Optics Europe Technical Digest · October 8, 2001
Phase dispersion optical tomography (PDOT) technique that eliminates interferometer jitter noise was analyzed. The input light was a pair of overlapped beams of laser light at wavelength λ and 2λ. The Gelatin and water layer sandwiched between two cover sl ...
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Journal ArticleApplied Optics · August 20, 2001
Dynamic light-scattering spectroscopy is used to study Brownian motion within highly scattering samples. The fluctuations of the light field that is backscattered by a suspension of polystyrene microspheres are measured as power spectra by use of low-coher ...
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Journal ArticleOptics Letters · August 15, 2001
We report a highly sensitive means of measuring cellular dynamics with a novel interferometer that can measure motional phase changes. The system is based on a modified Michelson interferometer with a composite laser beam of 1550-nm low-coherence light and ...
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Journal ArticleOptics Letters · May 15, 2001
We report on phase-dispersion optical tomography, a new imaging technique based on phase measurements using low-coherence interferometry. The technique simultaneously probes the target with fundamental and second-harmonic light and interferometrically meas ...
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Journal ArticleOptics Letters · March 15, 2001
We present a novel interferometer for measuring angular distributions of backscattered light. The new system exploits a low-coherence source in a modified Michelson interferometer to provide depth resolution, as in optical coherence tomography, but include ...
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Journal ArticleOptics Letters · February 15, 2001
Ballistic light, i.e., radiation that propagates undeflected through a turbid medium, undergoes a small change in phase velocity and exhibits unusual dispersion because of its wave nature. We use a novel highly sensitive differential phase optical interfer ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2001
We describe our phase-sensitive interferometry technique implemented as phase dispersion microscopy (PDM)/optical tomography (PDOT). The technique is based on measuring the phase difference between fundamental and second harmonic low coherence light in a n ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2001
A modified Michelson interferometer is used to measure path-length resolved angular distributions of light backscattered by turbid media. The path length resolution is obtained by exploiting the coherence properties of a broadband source. The angular distr ...
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Journal ArticleOptics and Photonics News · January 1, 2001
A low coherence phase-referenced interferometer (PRI) that can be used to measure slow and small movements with the objective of studying subcellular dynamics was presented. The use of low coherence light in the interferometer provides depth resolution and ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2001
A compact excitation-emission spectrofluorimeter system used to acquire tissue fluorescence and reflectance with fiber optic light delivery and collection is presented. Ten dye cells are pumped by a XeCl excimer laser, creating laser excitation from 308 nm ...
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Journal ArticleOptics Letters · October 15, 2000
We describe a new scanning microscopy technique, phase-dispersion microscopy (PDM). The technique is based on measuring the phase difference between the fundamental and the second-harmonic light in a novel interferometer. PDM is highly sensitive to subtle ...
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Journal ArticlePhysical review letters · July 2000
We demonstrate time-resolved measurement of optical phase-space distributions as a new probe for investigating the propagation of light in disordered media. Phase-space techniques measure the joint transverse position and momentum distribution of the scatt ...
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Journal ArticleJournal of biomedical optics · April 2000
Light scattering spectroscopy (LSS) is a new technique capable of accurately measuring the features of nuclei and other cellular organelles in situ. We present the considerations required to implement and interpret field-based detection in LSS, where the s ...
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ConferenceOptics Infobase Conference Papers · January 1, 2000
We interferometrically measure path-length resolved power spectra of light backscattered by turbid media undergoing Brownian motion. The results are compared to a theoretical treatment, which analyzes the total power spectra by the number of scattering eve ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2000
We explore enhanced backscatter from a random medium using time-resolved optical phase space measurement, i.e. measurement of joint position and momentum (x, p) distributions of the light field as a function of propagation time in the medium. Enhanced back ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 2000
We demonstrate the measurement of path-length-resolved optical phase space distributions as a new framework for exploring the evolution of optical coherence in a turbid medium. This method measures joint transverse position and momentum (i.e., angle) distr ...
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Journal ArticleOptics letters · October 1999
We demonstrate a two-window heterodyne method for measuring the x-p cross correlation, ??(*)(x)? (p)?, of an optical field ? for transverse position x and transverse momentum p. This scheme permits independent control of the x and p resolution. A simple li ...
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Journal ArticleJournal of biomedical optics · October 1999
Advances in optical coherence tomography (OCT) rely on the availability of broadband light that is spatially coherent. We present a technique to characterize coherence properties of broadband light using optical phase-space contours in transverse momentum ...
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Journal ArticleOptics letters · September 1999
Using a novel heterodyne technique, we measure optical phase-space distributions in momentum and position for low-coherence light. Quantitative information is obtained simultaneously about the longitudinal and the transverse coherence properties as well as ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 1999
We use heterodyne detection to characterize the Wigner phase space distribution W (x, p) of an optical field in position x and momentum p. This method yields smoothed Wigner phase space distributions directly as contour plots and can be applied with either ...
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Journal ArticleProceedings of SPIE the International Society for Optical Engineering · January 1, 1999
We use heterodyne detection to characterize the Wigner phase space distribution W(x, p) of an optical field in position x and momentum p. This method yields smoothed Wigner phase space distributions directly as contour plots and can be applied with either ...
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Journal ArticleJournal of the Optical Society of America. A, Optics, image science, and vision · July 1998
We study Wigner phase-space distributions W (x, p) in position (x) and momentum (p) for light undergoing multiple small-angle scattering in a turbid medium. Smoothed Wigner phase-space distributions are measured by using a heterodyne technique that achieve ...
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ConferenceOptics Infobase Conference Papers · January 1, 1998
We use a simple heterodyne method to measure smoothed Wigner phase space distributions for light transmitted through a turbid medium. A three component distribution is seen to emerge from the sample, consisting of a ballistic peak, a narrow diffractive ped ...
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Journal ArticleConference Proceedings Lasers and Electro Optics Society Annual Meeting LEOS · January 1, 1997
Smoothed Wigner phase space contours can be directly measured using a simple heterodyne detection-based optical system employing a He-Ne laser beam split into a 1 mW local oscillator and a 1 mW signal beam, and a spectrum analyzer for real time mean square ...
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Journal ArticleOptics letters · September 1996
We demonstrate that optical heterodyne imaging directly measures smoothed Wigner phase space distributions. This method may be broadly applicable to fundamental studies of light propagation and tomographic imaging. Basic physical properties of Wigner distr ...
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