Dr. Neelam Gupta Profile

Dr. Neelam Gupta

Physicist at US Army Research Lab

SPIE Involvement:

Conference Program Committee | Author

Publications (54)

PROCEEDINGS ARTICLE | September 18, 2018

Anomalous thermal expansion of mercurous halides

Proc. SPIE. 10766, Infrared Sensors, Devices, and Applications VIII

KEYWORDS: Fabrication, Long wavelength infrared, Diffraction, Visible radiation, Crystals, Modulators, Transmission electron microscopy, Infrared radiation, Bragg cells, Acousto-optics

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PROCEEDINGS ARTICLE | February 21, 2018

Characterization of tunable longwave infrared filters using quantum cascade lasers

Proc. SPIE. 10541, Photonic and Phononic Properties of Engineered Nanostructures VIII

KEYWORDS: Long wavelength infrared, Optical filters, Antireflective coatings, Polarization, Germanium, Dielectrics, Reflectivity, Quantum cascade lasers, Dielectric filters, Tunable filters

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PROCEEDINGS ARTICLE | August 30, 2017

Long wavelength infrared (LWIR) AOTF and AOM modulators using Hg2Br2 crystals

Proc. SPIE. 10404, Infrared Sensors, Devices, and Applications VII

KEYWORDS: Long wavelength infrared, Diffraction, Crystals, X-ray diffraction, Tunable filters, Bragg cells, Acousto-optics, Single crystal X-ray diffraction

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SPIE Journal Paper | July 20, 2017

Effects of sidelobes on acousto-optic tunable filter imaging

Gupta, Neelam , Suhre, Dennis

OE Vol. 56 Issue 07

KEYWORDS: Acousto-optics, Tunable filters, Imaging systems, Hyperspectral imaging, Infrared imaging, Infrared radiation, Image transmission, Ultraviolet radiation, Long wavelength infrared, Transducers

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PROCEEDINGS ARTICLE | February 16, 2017

Sidelobe considerations in AOTF imaging

Proc. SPIE. 10100, Optical Components and Materials XIV

KEYWORDS: Hyperspectral imaging, Short wave infrared radiation, Optical filters, Imaging systems, Cameras, Crystals, Semiconductor lasers, Confocal optics, Transducers, Acoustics

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An acousto-optic tunable filter (AOTF) is an all solid-state robust device with no-moving parts that has been used in the development of hyperspectral imagers from the ultraviolet to the longwave infrared. Such a device is fabricated by bonding a piezoelectric transducer on a specially cut prism in a birefringent crystal. When a radio frequency (RF) signal is applied to the transducer, a diffraction grating is set up in the crystal with grating period determined by the applied RF and the diffracted wavelength depends upon the applied RF and the prism parameters. When broadband white light is incident on the prism input facet, two orthogonally polarized diffracted beams at a specific wavelength with a narrow bandpass are transmitted for each applied RF. The transmitted wavelength can be tuned by varying the applied RF and this is used in a hyperspectral imager design. The spectral response of the transmitted intensity from an AOTF with a rectangular transducer has a sinc² distribution with a main lobe and a large number of sidelobes. In general, in hyperspectral imaging applications the light leakage from the sidelobes is not taken into account. When imaging is carried out for a scene with a laser or an intense source of light, the spectral images are affected by the light transmitted through these sidelobes away from the main lobe. We have carried out a detailed study of light transmitted through the sidelobes of a TeO₂ AOTF with a rectangular transducer operating in the shortwave infrared (SWIR) region from 0.9 to 1.7 μm. The AOTF imaging system used a telecentric confocal optics that compensates for AOTF aberrations, which are severe at high sidelobe operation. We used a 16-channel RF driver with independent amplitude and frequency control. By switching off specific RF signals applied to the AOTF, we measured the detailed sidelobe structure for the transmitted intensity by analyzing the spectral images and compared it with theoretical prediction. Here we present our experimental setup and results.

PROCEEDINGS ARTICLE | May 17, 2016

Acousto-optic tunable filter as a notch filter

Proc. SPIE. 9822, Advanced Optics for Defense Applications: UV through LWIR

KEYWORDS: Hyperspectral imaging, Short wave infrared radiation, Optical filters, Imaging systems, Cameras, Crystals, Linear filtering, Transducers, Acoustics, Acousto-optics

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PROCEEDINGS ARTICLE | May 12, 2016

Long wave infrared tunable filter based on guided mode resonant effect

Proc. SPIE. 9855, Next-Generation Spectroscopic Technologies IX

KEYWORDS: Long wavelength infrared, Optical filters, Waveguides, Polarization, Germanium, Dielectrics, Reflectivity, Infrared radiation, Dielectric filters, Tunable filters

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PROCEEDINGS ARTICLE | February 24, 2016

Design and fabrication of long wave infrared spectral filters

Proc. SPIE. 9744, Optical Components and Materials XIII

KEYWORDS: Long wavelength infrared, Plasmonics, Optical filters, Mirrors, Reflection, Germanium, Reflectivity, Infrared radiation, Absorption filters, Dielectric polarization

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PROCEEDINGS ARTICLE | August 26, 2015

Novel semiconductor radiation detector based on mercurous halides

Proc. SPIE. 9593, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVII

KEYWORDS: Semiconductors, Homeland security, Sensors, Electrodes, Crystals, Electrons, Sensor performance, Chlorine, Bromine, Commercial off the shelf technology

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PROCEEDINGS ARTICLE | June 3, 2015

Performance characterization of VNIR and SWIR spectropolarimetric imagers

Proc. SPIE. 9482, Next-Generation Spectroscopic Technologies VIII

KEYWORDS: Hyperspectral imaging, Short wave infrared radiation, Polarization, Imaging systems, Cameras, Crystals, Reflectivity, Tunable filters, Acoustics, Acousto-optics

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PROCEEDINGS ARTICLE | February 27, 2015

Large size MOEMS Fabry-Perot interferometer filter for focal plane array hyperspectral imaging

Proc. SPIE. 9375, MOEMS and Miniaturized Systems XIV

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Optical filters, Fabry–Perot interferometry, Electrodes, Silicon, Microopto electromechanical systems, Computer aided design, Electronic filtering

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PROCEEDINGS ARTICLE | May 21, 2014

Miniaturized imaging spectrometer based on Fabry-Perot MOEMS filters and HgCdTe infrared focal plane arrays

Proc. SPIE. 9100, Image Sensing Technologies: Materials, Devices, Systems, and Applications

KEYWORDS: Staring arrays, Long wavelength infrared, Infrared imaging, Spectroscopy, Interfaces, Reflectivity, Spectral resolution, Infrared radiation, Electronic filtering, Semiconducting wafers

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Imaging spectrometry can be utilized in the midwave infrared (MWIR) and long wave infrared (LWIR) bands to detect, identify and map complex chemical agents based on their rotational and vibrational emission spectra. Hyperspectral datasets are typically obtained using grating or Fourier transform spectrometers to separate the incoming light into spectral bands. At present, these spectrometers are large, cumbersome, slow and expensive, and their resolution is limited by bulky mechanical components such as mirrors and gratings. As such, low-cost, miniaturized imaging spectrometers are of great interest. Microfabrication of micro-electro-mechanicalsystems (MEMS)-based components opens the door for producing low-cost, reliable optical systems. We present here our work on developing a miniaturized IR imaging spectrometer by coupling a mercury cadmium telluride (HgCdTe)-based infrared focal plane array (FPA) with a MEMS-based Fabry-Perot filter (FPF). The two membranes are fabricated from silicon-oninsulator (SOI) wafers using bulk micromachining technology. The fixed membrane is a standard silicon membrane, fabricated using back etching processes. The movable membrane is implemented as an X-beam structure to improve mechanical stability. The geometries of the distributed Bragg reflector (DBR)-based tunable FPFs are modeled to achieve the desired spectral resolution and wavelength range. Additionally, acceptable fabrication tolerances are determined by modeling the spectral performance of the FPFs as a function of DBR surface roughness and membrane curvature. These fabrication non-idealities are then mitigated by developing an optimized DBR process flow yielding high-performance FPF cavities. Zinc Sulfide (ZnS) and Germanium (Ge) are chosen as the low and the high index materials, respectively, and are deposited using an electron beam process. Simulations are presented showing the impact of these changes and non-idealities in both a device and systems level.

PROCEEDINGS ARTICLE | May 21, 2014

Development of spectropolarimetric imagers from 400 to 1700 nm

Proc. SPIE. 9099, Polarization: Measurement, Analysis, and Remote Sensing XI

KEYWORDS: Hyperspectral imaging, Short wave infrared radiation, Polarization, Imaging systems, Cameras, Calibration, Crystals, Wave plates, Liquid crystals, Phase shifts

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PROCEEDINGS ARTICLE | May 21, 2014

Materials for imaging acousto-optic tunable filters

Proc. SPIE. 9100, Image Sensing Technologies: Materials, Devices, Systems, and Applications

KEYWORDS: Long wavelength infrared, Hyperspectral imaging, Optical filters, Imaging systems, Cameras, Ultraviolet radiation, Crystals, Transducers, Acoustics, Acousto-optics

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SPIE Journal Paper | March 13, 2014

Design and fabrication of Fabry–Perot filters for infrared hyperspectral imagers

Morley, Michael , Velicu, Silviu , Chang, Yong , Grein, Christoph , Kozak, Dmitry , Fernandez, Bautista , Kubby, Joel , Gupta, Neelam

JM3 Vol. 13 Issue 01

KEYWORDS: Electronic filtering, Reflectivity, Infrared imaging, Hyperspectral imaging, Imaging systems, Optical filters, Infrared radiation, Semiconducting wafers, Image filtering, Surface roughness

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PROCEEDINGS ARTICLE | March 7, 2014

Next generation miniature simultaneous multi-hyperspectral imaging systems

Proc. SPIE. 8977, MOEMS and Miniaturized Systems XIII

KEYWORDS: Staring arrays, Gold, Hyperspectral imaging, Mirrors, Fabry–Perot interferometers, Cameras, Microopto electromechanical systems, Spectral resolution, Tunable filters, Signal detection

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PROCEEDINGS ARTICLE | June 4, 2013

Characterization of SWIR hyperspectral imager with a multispectral polarized scene projector

Proc. SPIE. 8707, Technologies for Synthetic Environments: Hardware-in-the-Loop XVIII

KEYWORDS: Hyperspectral imaging, Short wave infrared radiation, Indium gallium arsenide, Polarization, Imaging systems, Cameras, Spatial light modulators, Liquid crystal on silicon, Projection systems, Tunable filters

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PROCEEDINGS ARTICLE | March 5, 2013

Hyperspectral Fabry-Perot filters for HgCdTe infrared detectors

Proc. SPIE. 8613, Advanced Fabrication Technologies for Micro/Nano Optics and Photonics VI

KEYWORDS: Infrared detectors, Long wavelength infrared, Optical filters, Mercury cadmium telluride, Sensors, Interfaces, Reflectivity, Zinc, Spectral resolution, Electronic filtering

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SPIE Journal Paper | July 19, 2012

Microelectromechanical systems-based visible-near infrared Fabry-Perot tunable filters using quartz substrate

Gupta, Neelam , Tan, Songsheng , Zander, Dennis

OE Vol. 51 Issue 7

KEYWORDS: Mirrors, Silver, Electrodes, Quartz, Tunable filters, Microelectromechanical systems, Fabry–Perot interferometers, Infrared imaging, Optical filters, Gold

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SPIE Journal Paper | July 16, 2012

Spectral imaging characterization of quartz MOEM tunable Fabry-Perot filter

Gupta, Neelam , Tan, Songsheng

JM3 Vol. 11 Issue 3

KEYWORDS: Optical filters, Mirrors, Image filtering, Tunable filters, Microopto electromechanical systems, Electrodes, Quartz, Imaging spectroscopy, Imaging systems, Fabry–Perot interferometers

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PROCEEDINGS ARTICLE | February 16, 2012

Spectral imaging characterization of MOEM tunable Fabry-Perot filter

Proc. SPIE. 8252, MOEMS and Miniaturized Systems XI

KEYWORDS: Hyperspectral imaging, Optical filters, Mirrors, Fabry–Perot interferometers, Imaging systems, Electrodes, Silver, Microopto electromechanical systems, Image filtering, Tunable filters

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PROCEEDINGS ARTICLE | May 13, 2011

Multispectral polarized scene projector (MPSP)

Proc. SPIE. 8015, Technologies for Synthetic Environments: Hardware-in-the-Loop XVI

KEYWORDS: Nonuniformity corrections, Short wave infrared radiation, Polarization, Sensors, Polarimetry, Spatial light modulators, Liquid crystal on silicon, Projection systems, Liquid crystals, Tunable filters

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PROCEEDINGS ARTICLE | May 12, 2011

MEMS-based tunable Fabry-Perot filters

Proc. SPIE. 8032, Next-Generation Spectroscopic Technologies IV

KEYWORDS: Gold, Optical filters, Mirrors, Fabry–Perot interferometers, Quartz, Electrodes, Silver, Transmittance, Tunable filters, Semiconducting wafers

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SPIE Journal Paper | March 1, 2011

Miniature snapshot multispectral imager

Gupta, Neelam , Ashe, Philip , Tan, Songsheng

OE Vol. 50 Issue 03

KEYWORDS: Optical filters, Image filtering, Imaging systems, Multispectral imaging, Cameras, Staring arrays, Microlens, Dielectric filters, Optical fabrication, Mirrors

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PROCEEDINGS ARTICLE | May 4, 2010

A miniature snapshot multispectral imager

Proc. SPIE. 7660, Infrared Technology and Applications XXXVI

KEYWORDS: Staring arrays, Optical filters, Fabry–Perot interferometers, Silica, Imaging systems, Cameras, Multispectral imaging, Microlens, Image filtering, Dielectric filters

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PROCEEDINGS ARTICLE | May 5, 2009

Development of an unattended ground sensor array using piezoresistive sensors

Proc. SPIE. 7333, Unattended Ground, Sea, and Air Sensor Technologies and Applications XI

KEYWORDS: Carbon, Electronics, Roads, Sensors, Metals, Resistance, Software development, Resistors, Unattended ground sensors, Piezoresistive sensors

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This paper discusses the development of an Unattended Ground Sensor based on an array of pressure sensors designed to be buried in the ground. This sensor array, along with the required software (still under development), will have the ability to distinguish between humans and animals based on the size and shape of the foot print. The technology may also be applied to determine the weight and type of vehicle traveling on a road. The sensor array consists of pressure sensitive resistors (piezoresistors) on 0.8 inch centers printed on a sheet of polyimide film. Although very large arrays might one day be screen printed, the arrays for this study have been printed using a syringe dispenser and a precision x-y computer controlled table. For the preliminary development, the array has been sized to 8X10 inches. The piezoresistive properties of the sensors are discussed and preliminary test data is presented. It is shown that the piezoresistive gauge factor (ΔR/R/ΔL/L) is roughly 10 times that of conventional metal strain gauges. Because the change in resistance is large compared to metal strain gauges, lower cost electronics can be used. The small net size and low mass enables sensing elements with fast response time. The fact that these piezoresistive elements are directly printed, as opposed to being adhesively attached to a surface, eliminates many of the issues associated with bonded discrete sensors. It is anticipated that the piezoresistive sensor approach presented in this paper will be well suited to extremely rugged environmental conditions compared to the commercially available sensor arrays which rely on surface contact resistance or capacitive sensors which can be easily destroyed by moisture. Environmental testing will be done in a future phase of the project. The final system, which is still under development, will consist of a sensor array, information processing, and RF signal transmission. The system is anticipated to be low cost and environmentally rugged.

PROCEEDINGS ARTICLE | May 5, 2009

LWIR hyperspectral imager based on a diffractive optics lens

Proc. SPIE. 7303, Detection and Sensing of Mines, Explosive Objects, and Obscured Targets XIV

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Imaging systems, Cameras, Image processing, Silicon, Image analysis, Aluminum, Absorption

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PROCEEDINGS ARTICLE | April 16, 2008

Comparison of QWIP to HgCdTe detectors for gas imaging

Proc. SPIE. 6940, Infrared Technology and Applications XXXIV

KEYWORDS: Mercury cadmium telluride, Imaging systems, Sensors, Aerosols, Spectrometers, Imaging spectroscopy, Detector arrays, Image sensors, Quantum well infrared photodetectors, Absorption

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PROCEEDINGS ARTICLE | April 16, 2008

Hyperspectral imager development at Army Research Laboratory

Proc. SPIE. 6940, Infrared Technology and Applications XXXIV

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Mid-IR, Fabry–Perot interferometers, Polarization, Imaging systems, Cameras, Ultraviolet radiation, Tunable filters

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Development of robust compact optical imagers that can acquire both spectral and spatial features from a scene of interest is of utmost importance for standoff detection of chemical and biological agents as well as targets and backgrounds. Spectral features arise due to the material properties of objects as a result of the emission, reflection, and absorption of light. Using hyperspectral imaging one can acquire images with narrow spectral bands and take advantage of the characteristic spectral signatures of different materials making up the scene in detection of objects. Traditional hyperspectral imaging systems use gratings and prisms that acquire one-dimensional spectral images and require relative motion of sensor and scene in addition to data processing to form a two-dimensional image cube. There is much interest in developing hyperspectral imagers using tunable filters that acquire a two-dimensional spectral image and build up an image cube as a function of time. At the Army Research Laboratory (ARL), we are developing hyperspectral imagers using a number of novel tunable filter technologies. These include acousto-optic tunable filters (AOTFs) that can provide adaptive no-moving-parts imagers from the UV to the long wave infrared, diffractive optics technology that can provide image cubes either in a single spectral region or simultaneously in different spectral regions using a single moving lens or by using a lenslet array, and micro-electromechanical systems (MEMS)-based Fabry-Perot (FP) tunable etalons to develop miniature sensors that take advantage of the advances in microfabrication and packaging technologies. New materials are being developed to design AOTFs and a full Stokes polarization imager has been developed, diffractive optics lenslet arrays are being explored, and novel FP tunable filters are under fabrication for the development of novel miniature hyperspectral imagers. Here we will brief on all the technologies being developed and present highlights of our research and development efforts.

PROCEEDINGS ARTICLE | March 31, 2008

Acousto-optic tunable filter based spectropolarimetric imagers

Proc. SPIE. 6972, Polarization: Measurement, Analysis, and Remote Sensing VIII

KEYWORDS: Hyperspectral imaging, Polarization, Imaging systems, Cameras, Ultraviolet radiation, Crystals, Wave plates, Tunable filters, Acoustics, Acousto-optics

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PROCEEDINGS ARTICLE | February 8, 2008

Detection of blood oxygen level by noninvasive passive spectral imaging of skin

Proc. SPIE. 6842, Photonic Therapeutics and Diagnostics IV

KEYWORDS: Hyperspectral imaging, Polarization, Imaging systems, Skin, Crystals, Imaging spectroscopy, Wave plates, Transducers, Liquid crystals, Acoustics

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PROCEEDINGS ARTICLE | September 12, 2007

Development of mercurous halide crystals for acousto-optic devices

Proc. SPIE. 6661, Imaging Spectrometry XII

KEYWORDS: Long wavelength infrared, Transparency, Crystals, Mercury, Transducers, Bragg cells, Chlorine, Acoustics, Acousto-optics, Bromine

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SPIE Journal Paper | June 1, 2007

Crystal growth, fabrication, and design of mercurous bromide acousto-optic tunable filters

Knuteson, David , Singh, Narsingh , Gottlieb, M. , Suhre, D. , Gupta, Neelam , Berghmans, Andre , Kahler, David , Wagner, Brian , Hawkins, Jack

OE Vol. 46 Issue 06

KEYWORDS: Crystals, Acousto-optics, Mercury, Bromine, Transducers, Acoustics, Tunable filters, X-rays, Polishing, Single crystal X-ray diffraction

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PROCEEDINGS ARTICLE | February 15, 2006

Fiber-coupled AOTF spectrometers

Proc. SPIE. 6083, Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications VI

KEYWORDS: Optical fibers, Sensors, Quartz, Ultraviolet radiation, Crystals, Spectrometers, Adaptive optics, Raman spectroscopy, Acoustics, Acousto-optics

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PROCEEDINGS ARTICLE | November 8, 2005

A simultaneous dual-band infrared hyperspectral imager for standoff detection

Proc. SPIE. 5995, Chemical and Biological Standoff Detection III

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Infrared imaging, Mid-IR, Standoff detection, Imaging systems, Cameras, Image processing, Absorption

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PROCEEDINGS ARTICLE | September 29, 2005

Acousto-optic tunable filters for infrared imaging

Proc. SPIE. 5953, Acousto-optics and Photoacoustics

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Infrared imaging, Mid-IR, Imaging systems, Cameras, Crystals, Mercury, Acousto-optics

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PROCEEDINGS ARTICLE | September 9, 2005

Design and fabrication of mercurous bromide acousto-optic filters

Proc. SPIE. 5881, Infrared and Photoelectronic Imagers and Detector Devices

KEYWORDS: Long wavelength infrared, Transparency, Crystals, X-rays, Mercury, Transducers, Tunable filters, Acoustics, Acousto-optics, Bromine

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PROCEEDINGS ARTICLE | September 7, 2005

Data collection with a dual-band infrared hyperspectral imager

Proc. SPIE. 5881, Infrared and Photoelectronic Imagers and Detector Devices

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Infrared imaging, Mid-IR, Imaging systems, Cameras, Image processing, Deconvolution, Infrared radiation

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SPIE Journal Paper | September 1, 2005

Acousto-optic-tunable-filter-based spectropolarimetric imagers for medical diagnostic applications—instrument design point of view

Gupta, Neelam

JBO Vol. 10 Issue 05

KEYWORDS: Imaging systems, Polarization, Ultraviolet radiation, Long wavelength infrared, Hyperspectral imaging, Crystals, Cameras, Medical diagnostics, Biomedical optics, Wave plates

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SPIE Journal Paper | September 1, 2005

Long-wave infrared spectral imager with an 8-cm^–1 passband acousto-optic tunable filter

Suhre, Dennis , Gupta, Neelam , Gottlieb, Milton

OE Vol. 44 Issue 09

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PROCEEDINGS ARTICLE | August 4, 2004

Design and fabrication of 2xD light emitting device arrays for IR scene projection

Proc. SPIE. 5408, Technologies for Synthetic Environments: Hardware-in-the-Loop Testing IX

KEYWORDS: Infrared cameras, Light emitting diodes, Sensors, Gallium antimonide, Black bodies, Infrared radiation, Analytical research, Resistors, Temperature metrology, Light

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PROCEEDINGS ARTICLE | February 27, 2004

Mid-wave IR liquid crystal tunable retarder for spectrapolarimetric imaging

Proc. SPIE. 5268, Chemical and Biological Standoff Detection

KEYWORDS: Mid-IR, Polarization, Birefringence, Imaging systems, Coating, Wave plates, Black bodies, Liquid crystals, Spinel, Absorption

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PROCEEDINGS ARTICLE | February 27, 2004

A no-moving-parts UV/visible hyperspectral imager

Proc. SPIE. 5268, Chemical and Biological Standoff Detection

KEYWORDS: Hyperspectral imaging, Optical filters, Imaging systems, Quartz, Ultraviolet radiation, Crystals, CCD cameras, Transducers, Acoustics, Acousto-optics

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SPIE Journal Paper | May 1, 2002

Acousto-optic tunable filter-based visible-to-near-infrared spectroploarimetric imager

Gupta, Neelam , Dahmani, Rachid , Choy, Steven

OE Vol. 41 Issue 05

KEYWORDS: Polarization, Imaging systems, Acousto-optics, Crystals, Tunable filters, Roads, Cameras, Acoustics, CCD cameras, Spectral resolution

PROCEEDINGS ARTICLE | February 7, 2002

Spectroscopic analysis of automotive engine oil

Proc. SPIE. 4574, Instrumentation for Air Pollution and Global Atmospheric Monitoring

KEYWORDS: FT-IR spectroscopy, Metals, Spectroscopy, Infrared spectroscopy, Absorption spectroscopy, Chemical analysis, Analytical research, Acousto-optics, Atmospheric particles, Absorption

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PROCEEDINGS ARTICLE | February 7, 2002

Tunable acousto-optic filters for monitoring of atmospheric ozone

Proc. SPIE. 4574, Instrumentation for Air Pollution and Global Atmospheric Monitoring

KEYWORDS: Signal to noise ratio, Optical filters, Quartz, Ultraviolet radiation, Crystals, Adaptive optics, Earth's atmosphere, Acoustics, Acousto-optics, Atmospheric monitoring

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PROCEEDINGS ARTICLE | February 7, 2002

Remote sensing using hyperspectral and polarization images

Proc. SPIE. 4574, Instrumentation for Air Pollution and Global Atmospheric Monitoring

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Infrared imaging, Polarization, Imaging systems, Remote sensing, Wave plates, Tunable filters, Infrared signatures

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PROCEEDINGS ARTICLE | November 15, 2000

Spectropolarimetric imaging using a field-portable imager

Proc. SPIE. 4132, Imaging Spectrometry VI

KEYWORDS: Target detection, Visible radiation, Roads, Polarization, Imaging systems, Metals, Polarimetry, Vegetation, Analytical research, Acousto-optics

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PROCEEDINGS ARTICLE | July 27, 2000

Progress in AOTF hyperspectral imagers

Proc. SPIE. 4054, Automated Geo-Spatial Image and Data Exploitation

KEYWORDS: Staring arrays, Long wavelength infrared, Hyperspectral imaging, Infrared imaging, Mercury cadmium telluride, Polarization, Imaging systems, Sensors, Crystals, Thallium

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PROCEEDINGS ARTICLE | September 24, 1999

Acousto-optic imaging in the mid-infrared region of the spectrum

Proc. SPIE. 3900, 3rd International Conference on Optical Information Processing

KEYWORDS: Infrared imaging, Diffraction, Optical filters, Image processing, Crystals, Transducers, Image filtering, Infrared radiation, Acoustics, Acousto-optics

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PROCEEDINGS ARTICLE | August 24, 1999

Hyperspectral imaging using acousto-optic tunable filters

Proc. SPIE. 3718, Automatic Target Recognition IX

KEYWORDS: Hyperspectral imaging, Optical filters, Polarization, Imaging systems, Image processing, Polarimetry, Image filtering, Tunable filters, Camouflage, Acousto-optics

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PROCEEDINGS ARTICLE | January 29, 1999

Multispectral and hyperspectral imaging with AOTF for object recognition

Proc. SPIE. 3584, 27th AIPR Workshop: Advances in Computer-Assisted Recognition

KEYWORDS: Hyperspectral imaging, Mid-IR, Optical filters, Polarization, Imaging systems, Image processing, Crystals, Multispectral imaging, Acoustics, Acousto-optics

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PROCEEDINGS ARTICLE | July 1, 1993

GaAs-waveguide-based optical neural network device architecture

Proc. SPIE. 1849, Optoelectronic Interconnects

KEYWORDS: Switches, Waveguides, Gallium arsenide, Modulators, Semiconductor lasers, Optoelectronics, Neural networks, Resistors, Stereolithography, Neurons

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PROCEEDINGS ARTICLE | June 1, 1990

Lithium niobate integrated-optics demonstration of optical control of microwaves

Proc. SPIE. 1217, Optoelectronic Signal Processing for Phased-Array Antennas II

KEYWORDS: Lithium niobate, Waveguides, Sensors, Integrated optics, Antennas, Bragg cells, Microwave radiation, Signal detection, Phased array optics, Phase shifts

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