The short-wave HgCdTe thin film material was grown by liquid phase epitaxy on CdTe substrate,Adopt n on p injection bonding and function and flip-flop mixing process,With a low noise readout circuit,sealed with a high...The short-wave HgCdTe thin film material was grown by liquid phase epitaxy on CdTe substrate,Adopt n on p injection bonding and function and flip-flop mixing process,With a low noise readout circuit,sealed with a high airtightness cellular-metal shell,Using a four-stage Thermo Electric Cooler(TEC),320×256 Short Wave Infrared Focal Plane Cooling Detecto r available to operate at near room temperature(210K).Its main photoelectric performance are signal-to-noise ratio greater than 400,nonuniformity equivalent to 4.69%,operability equivalent to 99.76%,frame rate equivalent to 115Hz,component weight less than 150grams.展开更多
Medium-wave HgCdTe thin films grown on germanium-based substrates by molecular beam epitaxy were treated by large area n-on-p injection junction and flip-flop mixing process.The chips interconnected with low-noise and...Medium-wave HgCdTe thin films grown on germanium-based substrates by molecular beam epitaxy were treated by large area n-on-p injection junction and flip-flop mixing process.The chips interconnected with low-noise and multimodal options readout circuit composed a 1280×1024 Medium-wave Infrared Focal Plane Cooling Detector whose pixel spacing was 15 microns.Its main photoelectric properties are average NETD equivalent to 18.5 mK,non-uniformity equivalent to 7.5%,operability equivalent to 98.97%.The paper also studies the substrate-removal technique on Germanium-based chip,which improves the stability and reliability of detector.展开更多
A semi-length focal plane detecting system for heavy ions has been built onthe Beijing Q3D magnetic spectrometer and tested by <sup>12</sup>C+<sup>197</sup>Au,<sup>16</sup>O+<sup...A semi-length focal plane detecting system for heavy ions has been built onthe Beijing Q3D magnetic spectrometer and tested by <sup>12</sup>C+<sup>197</sup>Au,<sup>16</sup>O+<sup>150</sup>Sm,and <sup>18</sup>O-<sup>156</sup>Gd reactions.The intrinsic resolutions of position and angle were 1.1 mmand 0.8°,respectively.The resolutions of energy loss ΔE,residual energy E<sub>R</sub> and totalenergy E<sub>T</sub> obtained were 3.0%,1.4% and 0.9%.respectively,after a special method ofdata processing was adopted.The achievable mass resolution is estimated to be about1.0% after necessary corrections for some signals concerned.Discussion aboul the edgeeffect of the detectors of this type is given too.展开更多
Room-temperature terahertz （THz） detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with differ...Room-temperature terahertz （THz） detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with different dimensions based on a micro-bridge structure have been designed and fabricated to get optimized micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium （Ti） thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer by a combined process of magnetron sputtering and reactive ion etching （RIE）, and its improvement of THz absorption is verified by an optical characteristics mesurement. Continuous-wave THz detection and imaging are demonstrated by using a 2.52 THz far infrared CO2 laser and a 320x240 vanadium oxide micro-bolometer focal plane array with an optimized cell structure. With this detecting system, THz imaging of metal concealed in a wiping cloth and an envelope is demonstrated, respectively.展开更多
We propose a substrate-free focal plane array （FPA） and the microcantilevers extend from a supporting frame. in this paper. The solid substrate is completely removed, Using finite element analysis, the thermal and m...We propose a substrate-free focal plane array （FPA） and the microcantilevers extend from a supporting frame. in this paper. The solid substrate is completely removed, Using finite element analysis, the thermal and mechanical characterizations of the substrate-free FPA are presented. Because of the large decrease in thermal conductance, the supporting frame is temperature dependent, which brings out a unique feature： the lower the thermal conductance of the supporting frame is, the higher the energy conversion efficiency in the substrate-free FPA will be. The results from the finite element analyses are consistent with our measurements： two types of substrate-free FPAs with pixel sizes of 200×200 and 60×60 um^2 are implemented in the proposed infrared detector. The noise equivalent temperature difference （NETD） values are experimentally measured to be 520 and 300 mK respectively. Further refinements are considered in various aspects, and the substrate-free FPA with a pixel size of 30×30 um^2 has a potential of achieving an NETD value of 10 mK.展开更多
As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum we...As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two color HgCdTe photodiodes and quantum well infrared photodetectors is presented. More attention is devoted to HgCdTe detectors. The two color detector arrays are based upon an n P N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials. Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP’s narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.展开更多
文摘The short-wave HgCdTe thin film material was grown by liquid phase epitaxy on CdTe substrate,Adopt n on p injection bonding and function and flip-flop mixing process,With a low noise readout circuit,sealed with a high airtightness cellular-metal shell,Using a four-stage Thermo Electric Cooler(TEC),320×256 Short Wave Infrared Focal Plane Cooling Detecto r available to operate at near room temperature(210K).Its main photoelectric performance are signal-to-noise ratio greater than 400,nonuniformity equivalent to 4.69%,operability equivalent to 99.76%,frame rate equivalent to 115Hz,component weight less than 150grams.
文摘Medium-wave HgCdTe thin films grown on germanium-based substrates by molecular beam epitaxy were treated by large area n-on-p injection junction and flip-flop mixing process.The chips interconnected with low-noise and multimodal options readout circuit composed a 1280×1024 Medium-wave Infrared Focal Plane Cooling Detector whose pixel spacing was 15 microns.Its main photoelectric properties are average NETD equivalent to 18.5 mK,non-uniformity equivalent to 7.5%,operability equivalent to 98.97%.The paper also studies the substrate-removal technique on Germanium-based chip,which improves the stability and reliability of detector.
文摘A semi-length focal plane detecting system for heavy ions has been built onthe Beijing Q3D magnetic spectrometer and tested by <sup>12</sup>C+<sup>197</sup>Au,<sup>16</sup>O+<sup>150</sup>Sm,and <sup>18</sup>O-<sup>156</sup>Gd reactions.The intrinsic resolutions of position and angle were 1.1 mmand 0.8°,respectively.The resolutions of energy loss ΔE,residual energy E<sub>R</sub> and totalenergy E<sub>T</sub> obtained were 3.0%,1.4% and 0.9%.respectively,after a special method ofdata processing was adopted.The achievable mass resolution is estimated to be about1.0% after necessary corrections for some signals concerned.Discussion aboul the edgeeffect of the detectors of this type is given too.
基金supported by the National Science Funds for Creative Research Groups of China under Grant No.61421002National High Technology Research and Development Program under Grant No.2015AA8123014
文摘Room-temperature terahertz （THz） detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with different dimensions based on a micro-bridge structure have been designed and fabricated to get optimized micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium （Ti） thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer by a combined process of magnetron sputtering and reactive ion etching （RIE）, and its improvement of THz absorption is verified by an optical characteristics mesurement. Continuous-wave THz detection and imaging are demonstrated by using a 2.52 THz far infrared CO2 laser and a 320x240 vanadium oxide micro-bolometer focal plane array with an optimized cell structure. With this detecting system, THz imaging of metal concealed in a wiping cloth and an envelope is demonstrated, respectively.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10732080 and 10627201)the National Basic Research Program of China (Grant No. 2006CB300404)
文摘We propose a substrate-free focal plane array （FPA） and the microcantilevers extend from a supporting frame. in this paper. The solid substrate is completely removed, Using finite element analysis, the thermal and mechanical characterizations of the substrate-free FPA are presented. Because of the large decrease in thermal conductance, the supporting frame is temperature dependent, which brings out a unique feature： the lower the thermal conductance of the supporting frame is, the higher the energy conversion efficiency in the substrate-free FPA will be. The results from the finite element analyses are consistent with our measurements： two types of substrate-free FPAs with pixel sizes of 200×200 and 60×60 um^2 are implemented in the proposed infrared detector. The noise equivalent temperature difference （NETD） values are experimentally measured to be 520 and 300 mK respectively. Further refinements are considered in various aspects, and the substrate-free FPA with a pixel size of 30×30 um^2 has a potential of achieving an NETD value of 10 mK.
文摘As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two color HgCdTe photodiodes and quantum well infrared photodetectors is presented. More attention is devoted to HgCdTe detectors. The two color detector arrays are based upon an n P N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials. Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP’s narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.
