A5108060801- Optical and Acousto-Optic Technologies
- Photorefractive and Nonlinear Optics
- Photonic and Optical Devices
- Solid-state spectroscopy and crystallography
- Crystal Structures and Properties
- Solid State Laser Technologies
- Photoacoustic and Ultrasonic Imaging
- Nonlinear Optical Materials Research
- Chalcogenide Semiconductor Thin Films
- Photochemistry and Electron Transfer Studies
- Semiconductor materials and devices
- Spectroscopy Techniques in Biomedical and Chemical Research
- Thermography and Photoacoustic Techniques
- Optical Polarization and Ellipsometry
- Advanced ceramic materials synthesis
- Luminescence Properties of Advanced Materials
- Silicon Carbide Semiconductor Technologies
- Optical properties and cooling technologies in crystalline materials
- Agricultural Economics and Practices
- Agricultural Science and Fertilization
- Biochemical and biochemical processes
- Glass properties and applications
- Advanced optical system design
- Advanced Semiconductor Detectors and Materials
- Fluid Dynamics and Heat Transfer
University of Maryland, Baltimore County
2012-2021
Northrop Grumman (United States)
2000-2011
Westinghouse Electric (United States)
1986-1994
GaSe crystals were doped with indium, and improvements in the mechanical properties second-harmonic efficiency over pure obtained. Both effects are due to an improvement crystal quality of material, it was shown that doping low levels indium did not alter intrinsic value nonlinear d coefficient.
New results achieved with recently grown Hg<sub>2</sub>Cl<sub>2</sub> and PbBr<sub>2</sub> crystals are described. With an optimized crystal growth technique were that show a significantly reduced acoustic attenuation compared to prior crystals, from 13.4 8 dB/μs-GHz<sup>2</sup>. These allow the development of Bragg cells time-bandwidth product figures in 5100 6900 range, frequency operation as high for Te02, resolution about 25% higher than TeO<sub>2</sub> similar lengths. also exhibit...
Acousto-optic tunable filter (AOTF) based imagers hold great promise for the emergence of next generation compact, lightweight, low-cost, programmable hyperspectral imaging systems that can solve problem data bottleneck as well provide polarization signatures better target detection and identification. At U.S. Army Research Laboratory, we have been developing such operate from visible to long infrared wavelengths. Some these used in laboratory field collection images. During past year,...
Mercurous chloride crystals, recently synthesized in large good optical quality boules by vapor deposition, have been characterized as to their unusual acoustooptic properties. This material offers the potential for superior performance Bragg cells signal processing and tunable filters. We developed fabrication techniques overcome severe problems associated with its high chemical reactivity, designed transducer structures, built tested a number of devices.
Mercurous bromide crystals with very good optical transparency were grown by the physical vapor transport method. A design was developed to fabricate 10-degree orientation acousto-optic tunable filters operating in mid and long wavelength regions. An filter (AOTF) fabricated using a crystal 13-15 mm diameter. theoretical tuning curve for mercurous based AOTF this also computed first time.
Some important results recently achieved with in-house grown high-quality, high-performance Hg<SUB>2</SUB>Cl<SUB>2</SUB> and PbBr<SUB>2</SUB> are described. Using an optimized crystal growth technique we have crystals that show a significantly reduced acoustic attenuation from 13.4 to 8 dB/microsecond(s) -GHz<SUP>2</SUP>. These allow the development of Bragg cells TBWP figures in 5,100 - 6,900 range, frequency operation as high TeO<SUB>2</SUB> resolution about 123% higher than for...
The authors have developed several binary, ternary, and quaternary selenide crystals for nonlinear optical (NLO) applications. present an overview of the crystal growth characterization bulk quasi-phase matched (QPM) their applications in mid-wave infrared (MWIR) long-wave (LWIR) regions. summarized growth, fabrication, performance gallium ternary compounds, silver selenide, thallium arsenic germanium crystals. Large are grown by Bridgman method from melt. These transmit up to 16 μm...
A collinear acousto-optic tunable filter (AOTF) is used to achieve all-electronic, rapid wavelength tuning (agility) of a pulsed CO<sub>2</sub> laser. Electronic intra-cavity laser selection demonstrated on both the P and R branches (00<sup>0</sup>1) - (10<sub>0</sub>0) band. An AOTF greatly expands flexibility affording 10-50 kHz switching rates, allowing broad-band (9-11 μm) coverage random access, basically rugged. This paper covers description by mechanism, design fabrication steps...
A field experiment was conducted at Kanpur during rabi seasons of 2005-06 and 2006-07 to elucidate the ef- fect raised bed planting on growth, yield, water use efficiency economics chickpea ( Cicer arietinum L.) under various irrigation depths. Results revealed that increased nodulation significantly by 30.0% nodule dry weight 44.4% over flat planting. Raised also encouraged compara- tively more root growth than as evident through higher root: shoot ratio. Branching podding were sig-...
We have developed several binary, ternary and quaternary sulfide selenide crystals for nonlinear optical applications present an overview on the crystal growth characterization of (NLO) conversion efficiency. summarized performance silver gallium (AgGaSe<sub>2</sub>), thallium arsenic (Tl<sub>3</sub>AsSe<sub>3</sub>), germanium (AgGaGe<sub>3</sub>Se<sub>8</sub> AgGaGe<sub>5</sub>Se<sub>12</sub>) compared with (GaSe). All these were grown by vertical Bridgman method in quartz ampoules using...
Northrop Grumman has designed, developed and demonstrated acousto-optic tunable filter (AOTF) based hyperspectral imager to cover visible long wavelength infrared (LWIR) spectral region. We have experimentally report the results of crystal growth, fabrication, design, development performance for (AOTF)-based on an efficient thallium arsenic selenide. The growth 40 mm diameter 15 cm crystals, 4.0 AOTF system design are presented. A concept was with high efficiency, resolution, throughput...
We have developed and fabricated a Tl<sub>3</sub>AsSe<sub>3</sub> (TAS) crystal based acousto-optic tunable filter (AOTF) for operation between the 8 to 12.0 μm wavelength regions. demonstrated peak efficiency greater than 60% with 10.6 source 2 watts of RF input power. This high should enable resolution large throuput AOTF imaging spectroscopic systems.