| Ultraviolet Electrically Injected Light Sources With Epitaxial ZnO-Based Heterojunctions |
AUG 2007 |
15 pages |
| Authors:
Pallab Bhattacharya; JAMIE PHILLIPS; MICHIGAN UNIV REGENTS ANN ARBOR DIV OF RESEARCH DEVELOPMENT AND ADMINISTRATION
|
 | In this effort, significant emphasis was placed on the epitaxial growth and in situ doping of ZnO for optoelectronic devices. The materials research efforts on ZnO have resulted in device-quality material on sapphire substrates for the desired laser diodes, where the eventual material quality improvements necessary for the devices are anticipated for future growth on ZnO substrates. P-type doping of ZnO was demonstrated using nitrogen, though the p-type behavior was ... |
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| SAPHIRE: A New Flat-Panel Digital Mammography Detector With Avalanche Photoconductor and High-Resolution Field Emitter Readout |
JUN 2006 |
33 pages |
| Authors:
Wei Zhao; STATE UNIV OF NEW YORK AT ALBANY RESEARCH FOUNDATION
|
| A new concept of flat-panel imager (FPI) with avalanche gain and high resolution (with 50 micron pixel size) is being investigated for improving the imaging performance of digital mammography at low dose and high spatial frequencies, which are critical for the detection of subtle breast abnormalities and the development of digital tomosynthesis. The detector employs an avalanche photoconductor - amorphous selenium (a-Se), called HARP, to detect and amplify the optical ... |
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| A New Flat-Panel Digital Mammography Detector with Avalanche Photoconductor and High-Resolution Field Emitter Readout |
JUN 2005 |
80 pages |
| Authors:
Wei Zhao; STATE UNIV OF NEW YORK AT STONY BROOK RESEARCH FOUNDATION
|
| A new concept of flat-panel imager (FPI) with avalanche gain and high resolution (with 50 micron pixel size) is being investigated for improving the imaging performance of digital mammography at low doses and high spatial frequencies, which are critical for the detection of subtle breast abnormalities and the development of digital tomosynthesis. The detector employs an avalanche photoconductor, amorphous selenium (a-Se), called HARP, to detect and amplify the optical signal ... |
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| Fast Photoconductivity in Self-Assembled Columnar Liquid Crystalline Photorefractive Materials |
30 JUL 2003 |
32 pages |
| Authors:
Kenneth D. Singer; Virgil Percec; CASE WESTERN RESERVE UNIV CLEVELAND OH
|
| We have elaborated a novel strategy for the self-assembly and co- assembly of functional supramolecular columns that self-organize in a hexagonal columnar liquid crystalline phase forming high carrier mobility organic semiconductor materials for applications in photorefractive and photovoltaic devices. Among our accomplishments are, (1) synthesis and elucidation of the structure of self-organizing dendron materials into a helical superstructure supporting an axial transport channel suggesting that structure and function can be ... |
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| Uncooled Photon Detectors for IR Imaging |
DEC 2002 |
61 pages |
| Authors:
M. Razeghi; H. Mohseni; Y. Wei; A. Gin; J. Bae; NORTHWESTERN UNIV EVANSTON IL CENTER FOR QUANTUM DEVICES
|
| Throughout the comprehensive research in the past three years, the unique properties of Type II InAs/GaSb heterojunctions were utilized for the realization of novel uncooled infrared photodetectors with higher operating temperature, detectivity and uniformity than the commonly available infrared detectors. |
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| Development of Liquid Crystal Spatial Light Modulators for mid-IR radiation, Addressed by Visible Radiation |
OCT 2002 |
37 pages |
| Authors:
Vladimir Y. Venediktov; INSTITUTE FOR LASER PHYSICS SAINT PETERSBURG (RUSSIA)
|
| This report results from a contract tasking Research Institute for Laser Physics as follows: Recent years has shown fast progress in the development of the technique of compensation for distortions in laser and imaging optical systems working in the visible spectral range through the use of dynamic holographic recording in optically-addressed liquid crystal spatial light modulators. However, this has not been extended to the mid-IR due to the lack of ... |
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| Frequency Difference Generation in the Terahertz Region Using LTG-GaAs Photodetector |
29 SEP 2000 |
4 pages |
| Authors:
E. Peytavit; G. Mouret; J. F. Lampin; P. Masselin; P. Mounaix; UNIVERSITE DU LITTORAL DUNKERQUE (FRANCE) LAB DE PHYSIQUE DES COMPOSANTS DE L'ATMOSPHERE
|
| We demonstrated Terahertz generation by optical frequency difference with a continuous tuning between 0.2 (^ 1 micro W ) and 3 THz (^1 nW). To this aim, high speed photodetectors with an interdigited photoconductor scheme on a submicron scale, loaded by THz log-periodic antennas, were deposited on a 1 micrometer-thick Low Temperature Grown (200 deg C) GaAs epilayer. Two Ti:Sapphire laser beams (^ 30 mW) focused onto the device yield ... |
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| Ultrabroadband Detection of Terahertz Radiation up to 20 THz with an LT-GaAs Photoconductive Antenna Gated by a 15-fs Laser Pulses |
29 SEP 2000 |
3 pages |
| Authors:
Shunsuke Kono; Masahiko Tani; Ping Gu; Kiyomi Sakai; KANSAI ADVANCED REASEARCH LAB KOBE (JAPAN) COMMUNICATIONS RESEARCH LAB
|
| We report on the ultrabroadband detection of terahertz radiation with a low-temperature grown GaAs photoconductive dipole antenna gated with 15-fs laser pulses. The detected spectral frequency exceeds 20 THz. This is the highest frequency detected with a photoconductive antenna reported so far. |
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| Imaging of Photoexcited Carrier Distribution in Semiconductors by THz Beams |
29 SEP 2000 |
4 pages |
| Authors:
Masanori Hangyo; Masatsugu Yamashita; Yoshiaki Kitoh; Masayoshi Tonouchi; OSAKA UNIV (JAPAN) RESEARCH CENTER FORSUPERCONDUCTOR PHOTONICS
|
| A terahertz (THz) wave imaging system using photoconductive antennas as an emitter and detector has been constructed and the focussing characteristics of the beam near the sample position has been investigated. By using this system, the images of photoexcited carrier distribution in silicon have been obtained with spatial resolution of 2.5 mm by measuring the transmission of the focused THz beams. |
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| Electrical Detection of THz Frequencies by Asymmetrically Shaped n-n(+)-GaAs Diodes |
29 SEP 2000 |
3 pages |
| Authors:
Algirdas Suziedelis; Jonas Gradauskas; Steponas Asmontas; Gintaras Valusis; Harmut G. Roskos; SEMICONDUCTOR PHYSICS INST VILNIUS (LITHUANIA)
|
| We propose a planar diode based on a thin asymmetrically-shaped n-n(+)-GaAs junction prepared on an elastic polyimide film as THz detector. The device can be used to detect electromagnetic radiation in the range from 0.129 THz up to 2.5 THz at room temperature. The principle of operation of the device is based on non-uniform carrier heating effects caused by both the asymmetrical shape of the structure and the presence of ... |
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| Spatial Pattern Formation of Optically Excited Carriers in Photoconductive THz Antennas |
29 SEP 2000 |
3 pages |
| Authors:
M. Bieler; G. Hein; K. Pierz; U. Siegner; M. Koch; PHYSIKALISCH-TECHNISCHE BUNDESANSTALT BRAUNSCHWEIG (GERMANY)
|
| We have investigated the role of spatio-temporal carrier dynamics in photoconductive THz antennas. To this end, the photoluminescence from a GaAs/AlGaAs quantum well has been spatially resolved after femtosecond laser excitation for different electric bias fields applied in the plane of the well. The photoluminescence patterns demonstrate substantially different electron-hole dynamics across the excitation laser spot. The density dependence of screening combines with the lateral variation of the carrier density ... |
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| Clinical and Technical Performance Evaluation of a Digital Mammography System |
JUL 2000 |
108 pages |
| Authors:
Ronald Schilling; PRIMEX GENERAL IMAGING CARLSBAD CA
|
| A slot-scanning digital mammography system was designed, constructed and tested to determine if improved image quality can improve the diagnostic quality of mammograms or to show that the same image quality can be provided at a lower patient dose. Technical evaluation of image data showed improved image quality over screen-film mammography. Not all of the design parameters of the system were met and further improvements ... |
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| Polarization Sensitive QWIP Thermal Imager |
MAR 2000 |
12 pages |
| Authors:
James Van Anda; Daniel W. Beekman; DIGITAL IMAGING INC APOPKA FL
|
| A polarization-sensitive thermal imager has been assembled using a quantum-well infrared photodetector (QWIP) focal plane array (FPA) with peak responsivity in the long-wave infrared (LWIR) spectral band near 9 micrometers. Polarization-dependent responsivity is achieved by etching linear gratings onto each pixel during QWIP FPA fabrication, with adjacent pixels having orthogonal grating orientation. The direct integration of the gratings with the pixels eliminates all pixel registration errors encountered with previous infrared ... |
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| Novel Field Deployable Flat Panel X-ray Imaging System |
FEB 1997 |
|
| Authors:
Richard Aikens; XICON TECHNOLOGIES FARMINGTON CT
|
 | This Phase I SBIR project relates to an X-ray image capture device under development by Xicon Technologies, LLC and the University of Connecticut (UConn). The X-ray Sensitive Electron Beam Image Tube (XEBIT), based on a proprietary high performance X-ray photoconductor, has been demonstrated in a nine inch diameter prototype with imaging performance exceeding that of all X- ray imaging media in use and those known to be in development. The ... |
|
| OSA Trends in Optics and Photonics Series. Volume 13: Ultrafast Electronics and Optoelectronics |
1997 |
311 pages |
| Authors:
Martin Nuss; John Bowers; OPTICAL SOCIETY OF AMERICA WASHINGTON DC
|
| This report is a compilation of papers concerning trends in optics and photonics. Specific topics include: (1) lasers, (2) communications, (3) devices, (4) high speed electronics, (5) measurement techniques, (6) terahertz optoelectronics, and (7) ultrafast dynamics. |
|
| The Study of Possibility to Implement the Dynamic Nonlinear-Optical Corrector Based on the Use of the Optical Negative-Feedback Loop for Correction for Distortions of Large Scale Optics |
97 |
68 pages |
| Authors:
Vladimir Y. Venediktov; STATE OPTICAL INST LENINGRAD (USSR)
|
| This report results from a contract tasking Research institute for Laser Physics as follows: The contractor will perform a comparative analysis of approaches to overcoming the 2 pi problem in nonlinear optical feedback correction schemes and determine an optimal solution. |
|
| Solid State Research |
15 FEB 96 |
|
| Authors:
David C. Shaver; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
| This report covers in detail tbe research work of the Solid State Division at Lincoln Laboratory for the period 1 November 1995-31 January 1996. The topics covered are Electrooptical Devices, Quantum Electronics, Materials Research, Submicrometer Technology, High Speed Electronics, Microelectronics, and Analog Device Technology. |
|
| Metalorganic Chemical Vapor Deposition of GaN, AlN and GaAlN for UV photodetector Applications |
APR 95 |
59 pages |
| Authors:
Manijeh Razeghi; NORTHWESTERN UNIV EVANSTON IL DEPT OF ELECTRICAL ENGINEERING
|
| GaN, AlN and GaAlN epilayers were grown by low-pressure metalorganic chemical vapor deposition, on sapphire, silicon, and 6H-SiC. The X-ray diffraction linewidths were as low as 30 and 100 arcsecs for GaN and AlN respectively on sapphire. Sharp optical absorption edges were obtained for these films. Transmission electron microscopy characterized the films microstructurally. Photoluminescence (PL) at 300 and 77 K yielded linewidths of about 80 and 40 meV respectively for ... |
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| Gigabit Optical Interconnects: System and Component Analysis, Design and Development |
JUL 94 |
26 pages |
| Authors:
Raymond K. Boncek; Mark F. Krol; Michael J. Hayduk; John L. Stacy; Steven T. Johns; ROME LAB GRIFFISS AFB NY
|
| This report describes the results of experiments performed in various areas of technology required to develop gigabit optical interconnects for communication at 1.3 micrometer wavelength. First, we will summarize the analysis of optical correlation switches (i.e. optical AND gates) for use in time-division optical interconnects. Next, we describe the design and characterization of an all-optical, 30db contrast ratio GaAlInAs multiple quantum well asymmetric reflection modulator. Then, we comment on the ... |
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| Integrated Photonics Research (1993) |
JUN 94 |
540 pages |
| Authors:
Yaron Silberberg; OPTICAL SOCIETY OF AMERICA WASHINGTON DC
|
| Summaries of papers presented at the Integrated Photonics Research Topical Meeting, March 22-24, 1993, in Palm Springs, California. Sessions include Novel Material and Devices, Time Domain Methods, Photonic Circuits and Lightwave Reception, III-V Semiconductor Switches and Modulators, Wavelength Selective Components, Optical Waveguide Simulators, Optical Switching, Silica on Silicon, Nonlinear Wave Propagation, Semiconductor Lasers, LiNbO3 and LiTaO3 Devices, Beam Propagation Methods, Photonic Integrated Circuits and Applications, Semiconductor Device Modeling, Waveguide Frequency ... |
|
| Report for AFOSR Contract F49620-92-J-052 (University of New Mexico) |
19 MAY 94 |
11 pages |
| Authors:
Steve Hersee; Kevin J. Malloy; NEW MEXICO UNIV ALBUQUERQUE
|
| The major accomplishments under this contract were the development of a quantum well intersubband photoconductive (QUIP) IR detector growth and fabrication process and characterization of GaN-based ultraviolet detectors. (MM) |
|
| Optically Switched Submillimeter-Wave Oscillator |
08 FEB 94 |
29 pages |
| Authors:
Michael G. Spencer; Xiao Tang; HOWARD UNIV WASHINGTON DC
|
| There exists a critical need for efficient local oscillators for heterodyne mixers operating in the 300 to 3000 GHz region. Applications include space-based submillimeter wave imaging arrays, airborne atmosphere spectroscopy, all-weather imaging radar, non-destructive testing, plasma diagnostics, weapon and contraband detection and communications. In order to address these problems, we propose a novel low power semiconductor device which uses time delays from a common optical pulse train to achieve a ... |
|
| InTISb for Long-Wavelength Infrared Photodetectors and Arrays |
94 |
14 pages |
| Authors:
Manijeh Razeghi; NORTHWESTERN UNIV EVANSTON IL DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCI ENCE
|
| The objective of this research program is to grow InTlSb alloys for long-wavelength infrared detectors by low-pressure metalorganic chemical vapor deposition and to investigate their physical properties. As the start towards this goal, optimum growth conditions for high quality InSb epitaxial films on InSb, GaAs, and Si have been determined. InSb films grown under these conditions exhibited one of the best structural and electrical properties reported so far. Growth of ... |
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| Multichip Module High Speed Testing |
31 DEC 93 |
4 pages |
| Authors:
Robert J. Davis; David H. Auston; COLUMBIA UNIV NEW YORK DEPT OF ELECTRICAL ENGINEERING
|
| Last quarter, we reported Al/SiO2/Al capacitor structures formed on an optical fiber, as the first step toward an electrooptic test probe. We have now fabricated an amorphous hydrogenated silicon (a-Si:H) photodetector directly on an optical fiber. We have been investigating the use of electrooptically active polymers for the purpose of electrooptic testing. Important problems remaining to be solved are low electrooptic efficiency and geometry; detection system speed, efficiency, and noise; ... |
|
| Study of the Homogeneity of InP Wafers |
JUL 93 |
79 pages |
| Authors:
J. Jimenez; P. Martin; M. Avella; VALLADOLID UNIV (SPAIN) SISICA DE LA MATERIA CONVENSADA
|
| The homogeneity of InP substrate at both microscope and microscopic scale has been studied by Raman microprobe and photocurrent mapping. Raman microprobe was used for any type of substrate, revealing revealing different structural and electronic properties of different extended defects. This study was correlated with photoetching and a relation between revealed defects and Raman features was established. Semiinsulating substrate were analyzed by photocurrent mapping. Three excitation wave lengths were used, ... |
|
| Light-Activated Solid-State Opening Switch |
JAN 93 |
10 pages |
| Authors:
Mark W. Heyse; Rodney A. Petr; George I. Kachen; James P. Reilly; Raymond B. Schaefer; WRIGHT LAB EGLIN AFB FL
|
| Light-activated solid-state opening switches are shown to be a viable approach for switching inductive circuits. Measured photoswitch performance indicates that light-activated opening switches have the power density ratings needed to develop compact inductive power systems.... High current opening switch, Solid state switches, Cryogenic silicon switches, Photoconductor switches. |
|
| Non-Steady-State PhotoEMF in Crystals with Long Relaxation Times of Photoconductivity, |
22 MAY 1992 |
|
| Authors:
I. A. Sokolov; S. I. Stepanov; AKADEMIYA NAUK SSSR LENINGRAD FIZIKO-TEKHNICHESKII INSTITUT
|
| The recently discovered effect of non-steady-state photo(EMF) is a powerful technique for the measurement of different parameters of photorefractive crystals. The photoEMF is observed as an alternating electric current J to the omega through a short-circuited sample of photoconductor illuminated by a vibrating pattern of interference between two coherent waves, one of-which is phase modulated with frequency omega. It results from a periodic modulation of the spatial shift between the ... |
|
| 100-GHz Electro-Optic S-Parameter Characterization of High-Electron-Mobility Transistors, |
22 MAY 1992 |
|
| Authors:
M. Y. Frankel; J. F. Whitaker; G. A. Mourou; J. A. Valdmanis; P. M. Smith; MICHIGAN UNIV ANN ARBOR ULTRAFAST SCIENCE LAB
|
| Progress in the research of modern semiconductor devices has advanced their response frequencies above 400 GHz. Such performance exceeds the conventional, purely electronic test instrumentation bandwidth, with the major limitations being imposed by the connectors and waveguides that are required for signal coupling to the device under test. This lack of convenient and accurate high-bandwidth device characterization methods imposes a serious obstacle to progress in semiconductor device development and utilization. ... |
|
| Large-Aperture Photoconducting Antennas, |
22 MAY 1992 |
|
| Authors:
D. H. Auston; X. -C. Zhang; COLUMBIA UNIV NEW YORK
|
| We describe a novel optoelectronic technique to generate and detect THz electromagnetic waves by using large-aperture planar photoconducting antennas and antenna arrays. This approach is an effective method of producing directional and steerable sub-millimeter wave pulses. |
|
| Photoactivated Switches and Applications |
DEC 1991 |
3 pages |
| Authors:
G. P. Imthurn; C. T. Chang; G. A. Garcia; D. J. Albares; NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA
|
| Photoactivated or optoelectronic switches whose resistance is controlled by light are being developed by DARPA at NOSC for sampling and control of electrical signals. The benefits offered include high speed, signal- control isolation, and compatibility with RF/microwave transmission lines. Furthermore the use of optical fibers to transmit light to the switches, yields complete switch isolation, absence of pickup, excellent timing control, and low jitter. Several application areas are being studied ... |
|
| Electro-Optic Generation and Detection of Femtosecond Electromagnetic Pulses |
20 NOV 91 |
30 pages |
| Authors:
David H. Auston; COLUMBIA UNIV NEW YORK DEPT OF ELECTRICAL ENGINEERING
|
| Key accomplishments during this period are: (1) The successful demonstration of a new technique for generating subpicosecond electromagnetic pulses using large aperture photoconductors to produce directional and diffraction-limited beams of terahertz radiation; (2) The development of a new electrically-controlled phased array of photoconducting antennas for producing steerable terahertz radiation; (3) The extraction of femtosecond electromagnetic pulses from an electro-optic crystal following their generation by electro-optic Cherenkov radiation, and their subsequent ... |
|
| Electrochemistry and Spectroelectrochemistry of 1,8-Naphthalene and 1,8- Anthracene-Linked Cofacial Binuclear Metallophthalocynanines. New Mixed Valence Metallopthalocyanines |
10 MAY 90 |
58 pages |
| Authors:
N. Kobayashi; H. Lam; W. A. Nevin; P. Janda; C. C. Leznoff; YORK UNIV DOWNSVIEW (ONTARIO) DEPT OF CHEMISTRY
|
| 1,8-Napthalene or 1,8-anthracene-linked cofacial dizinc, dicopper, and dicobalt diphthalocyanines have been studied by solution and surface electrochemistry, spectroelectrochemistry, and electron spin resonance (ESR). These derivatives are mixtures of syn and anti isomers which have very similar electrochemistry except where we comment specifically. The phthalocyanine ring first oxidation phthalocyanine, the Cobalt(III)/Cobalt(II) and Cobalt(II)/ cobalt(I) redox couples split into two couples as a consequence of intra-ring exchange interactions. The spectra of the ... |
|
| Soluble Polysilanes: A New Class of Radiation Sensitive O2-Rie Resistant Polymers for Use in Microlithography |
12 MAR 90 |
28 pages |
| Authors:
R. D. Miller; IBM ALMADEN RESEARCH CENTER SAN JOSE CA
|
| This report describes the progress in the synthesis, characterization and spectroscopy of soluble polysilanes and germanes. It includes polymer structural studies, theoretical investigations of electronic structure and mechanistic studies of the photodecomposition. It also describes the potential of these materials as polymeric photoconductors, and as new materials for microlithography. The initial work on the nonlinear optical characteristics of these materials is also included. Keywords: Polysilane; Synthesis; Spectroscopy; Photochemistry applications. (sdw) ... |
|
| Nonlinear Dynamics in Semiconductors |
30 JUN 89 |
9 pages |
| Authors:
Robert M. Westervelt; HARVARD UNIV CAMBRIDGE MA DIV OF APPLIED SCIENCES
|
| Important progress has been made in understanding the dynamics of space charge domains in cooled photoconductors has been made in experimental tests of the universal structure of frequency locking in driven oscillators, and in the dynamics of electronic neural networks. In addition, we have investigated a number of different approaches to the problem of 1/f noise. |
|
| OSA Proceedings on Picosecond Electronics and Optoelectronics. Volume 4 |
89 |
282 pages |
| Authors:
T. C. Sollner; David M. Bloom; OPTICAL SOCIETY OF AMERICA WASHINGTON DC
|
| Partial Symposia Contents: High-Speed Lightwave Systems; Ultrafast All-Optical Multiplexing-Demultiplexing Techniques for Future Optical Communications; Picosecond Pulse Generation and Sampling with GaAs Monolithic Integrated Circuits. Investigation of Picosecond Time-Resolved Photoluminescence in Gallium Arsenide with micron Spatial Resolution; Differential Sampling with Picosecond Resolution Using Bulk Photoconductors; Picosecond, Spatially Resolved Optical Detection of Charge-Density Modulation in A1GaAs Lasers; Ultrafast Nonlinearities in In GaAsP Diode Laser Amplifiers; Spread-Spectrum-Integrated Optic Modulators; Subpicosecond Multiple Pulse Formation ... |
|
| Low Power Liquid Crystal Display Backlight. |
05 OCT 1988 |
|
| Authors:
Daniel S. Lenko; Wayne R. Grine; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A liquid crystal display panel is disclosed having a backlight for providing high brightness, uniformity of illumination intensity, high efficiency, and long battery life, and which can be manufactured at a low cost. The display device includes a liquid crystal display panel, a light source for illuminating the liquid crystal panel, a light passage member which can be formed of a transparent material disposed between the liquid crystal panel and ... |
|
| Joint Services Electronics Program |
MAY 88 |
15 pages |
| Authors:
George W. Flynn; Richard M. Osgood Jr; COLUMBIA RADIATION LAB NEW YORK
|
| Several milestones have been reached in GaAs research. The first active GaAs device, a 1 micrometers channel width MESFET, has been made at Columbia. This device is a basic building block in the GaAs CCD program. GaAs surface studies have also born fruit. UV light has been found to oxidize rapidly the surface of GaAs in an UHV environment containing traces of water vapor and O2. The mechanism appears to ... |
|
| Infrared-Sensitive Spatial Light Modulator |
NOV 87 |
|
| Authors:
Cardinal Warde; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF ELECTRICAL ENGINEERING AND COMPU TER SCIENCE
|
| This final report summarizes a preliminary investigation of an infrared-sensitive spatial light modulator that is designed to respond to write light in the 3 to 5 micrometers wavelength range. The device can be read out with visible light and, as such, is intended to function simultaneously as an image wavelength upconverter and light modulator. The device design employs a thin-film InSb photoconductor that addresses a DKDP crystal which is cooled ... |
|
| Wide-Dynamic-Range Analog-to-Digital Conversion for HFDF |
NOV 86 |
|
| Authors:
W. H. McKnight; D. J. Kaplan; J. M. Speiser; T. O. Jones; NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
|
| Progress is reported in the development of the linear predictive coding/high-speed photoconductor sampling switch concept for wide-dynamic-range digitization of wideband HFDF data, using a synchronously driven laser/fiber- optic system. Development activity reported is in the areas of: (1) simulation, modeling, analysis, and demonstration of noise/jammer approach, using linear predictive coding for speech data; (2) assessment of a finite-impulse-response digital filter approach, using a tapped delay line with fixed tap weights ... |
|
| Amorphous Silicon Spatial Light Modulator. |
23 DEC 1985 |
|
| Authors:
Paul R. Ashley; DEPARTMENT OF THE ARMY WASHINGTON DC
|
| This patent application discloses an amorphous silicon spatial light modulator that includes a unique three electrode structure that is used to create a two-dimensional electric field distribution in liquid crystal material. This modulator allows for the use of very thin photoconductor layers and a middle electrode in the form of a grating structure to provide control of the field shape while also providing for high spatial resolution. |
|
| Blue Laser |
DEC 85 |
|
| Authors:
Gordon R. Griffin; XEROX SPECIAL INFORMATION SYSTEMS PASADENA CA
|
| This has been a development program to design a low noise, moderate power, blue, hollow cathode laser used for imaging on photoconductors for on- demand color printing. Descriptions of the construction, processing, and testing of experimental unit are presented with recommendations for design improvements. Keywords include: Hollow cathode laser; Blue laser; Low noise laser; He-Cd laser; Metal vapor laser and Gas laser. |
|
| A Comparison of Signal-to-Noise Ratios for Near-Infrared Detectors |
30 JAN 1984 |
|
| Authors:
J. E. Freeman; G. M. Hieftje; INDIANA UNIV AT BLOOMINGTON DEPT OF CHEMISTRY
|
| Five detectors sensitive in the near-infrared, including two photomultiplier tubes, a silicon photodiode, a silicon photodiode arry, and a lead-sulfide photoconductor, are evaluated in terms of signal-to-noise ratios. Theorectical noise and signal calculations are compared to measured noise values and relative responses. The spectral response of the detectors between 700 and 1200 nm is also reported. The relative merits of a particular detector are a function of wavelength, photon flux ... |
|
| Assessment of the Potential of Langmuir-Blodgett Films for Room Temperature IR (Infrared) Detectors |
30 SEP 1983 |
|
| Authors:
A. D. Schnitzler; BDM CORP MCLEAN VA
|
| Langmuir-Blodgett films possess high dielectric breakdown voltages and induce low surface state densities on semiconductor surfaces. These properties are valuable for surface passivation in manufacture of infrared detectors. It was suggested that these properties might be exploited in the fabrication of mercury cadmium telluride IR detectors that could operate at room temperature. However, examination of the temperature dependence of the fundamental thermal noise sources in LWIR detectors indicate that these ... |
|
| Solid State Research work of the Solid State Division at Lincoln Laboratory |
15 MAY 1983 |
|
| Authors:
Alan L. McWhorter; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
| This report covers in detail the solid state research work of the Solid State Division at Lincoln Laboratory for the period 1 February through 30 April 1983. The topics covered are Solid State Device Research, Quantum Electronics, Materials Research, Microelectronics, and Analog Device Technology. Funding is primarily provided by the Air Force, with additional support provided by the Army, DARPA, Navy, NASA, and DOE. (Author) |
|
| Solid State Research |
15 NOV 1982 |
|
| Authors:
Alan L. McWhorter; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
| This report covers in detail the solid state research work of the Solid State Division at Lincoln Laboratory for the period 1 August through 31 October 1982. The topics covered are Solid State Device Research, Quantum Electronics, Materials Research, Microelectronics, and Analog Device Technology. Funding is primarily provided by the Air Force, with additional support provided by the Army, DARPA, Navy, NASA, and DOE. |
|
| Optical-Microwave Interactions in Semiconductor Devices. |
MAR 1981 |
|
| Authors:
L. Figueroa; C. W. Slayman; H. W. Yen; HUGHES RESEARCH LABS MALIBU CA
|
| The results of an extensive characterization of microwave-optical devices is presented. The study has concentrated in the optical injection locking of IMPATT oscillators, high-speed analog modulation of (GaAl)As injection laser, mode-locking of (GaAl)As injection laser, and high-speed optical detectors. |
|
| Liquid Crystal Reflection Cell with Improved Response Times, |
23 JUN 1980 |
|
| Authors:
Herbert Hacker; I. Lefkowitz; R. Lontz; DUKE UNIV DURHAM NC DEPT OF ELECTRICAL ENGINEERING
|
|
| Ge:Ga Photoconductors in Low Infrared Backgrounds, |
29 JAN 1979 |
|
| Authors:
E. E. Haller; M. R. Hueschen; P. L. Richards; CALIFORNIA UNIV BERKELEY LAWRENCE BERKELEY LAB
|
| Photon noise limited performance of photoconductive detectors made from gallium doped germanium in very low infrared backgrounds (less than or equal to ten to the minus 8th power incident photons per second) is reported in this report. These detectors were made from a large volume crystal of Ge:Ga of the quality used for lithium drifted germanium gamma-ray spectrometers. This material contained very low concentrations of deep traps and minority impurities ... |
|
| Room-Temperature, Thin-Film, PBS Photoconductive Detector Hardened against Laser Damage. |
26 SEP 1978 |
|
| Authors:
Melvin R. Kruer ; Leon Esterowitz; Filbert J. Bartoli; Roger E. Allen; DEPARTMENT OF THE NAVY WASHINGTON D C
|
| Describes a photoconductive detector comprising a thin film of photoconductive material deposited on a thin substrate of high thermal conductivity having a surface area that is large relative to the detector's absorbing surface area. The back surface of the substrate is metalized and soldered to a high-thermal-conductivity, large-thermal-mass heat buffer which is coupled to a heat sink. The resulting detector is hardened against damage resulting from laser irradiation. (Author) |
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| Investigations of the Photoconductor-Thermoplastic Image Transducer. |
MAY 1978 |
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| Authors:
Willis S. Colburn; ENVIRONMENTAL RESEARCH INST OF MICHIGAN ANN ARBOR
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| A basic research effort was performed to investigate the use of the photoconductor-thermoplastic (PTP) recording medium as an incoherent-to-coherent transducer that serves as a real-time input device for an optical data processor. The principle of operation of the PTP recording medium is reviewed with a brief discussion of nonlinearities. We describe experimental investigations of the write-time, repetitive writing, resolution, response to a CRT input, and addition of an integral grating. ... |
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Reports by Keyword(s)
PHOTOCONDUCTORS
