Contents
2021
Volume: 42 Issue 3
8 Article(s)
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Research Progress of Type-II Superlattice Long-wave Infrared Detector
Wei-rong XING, Ming LIU, Tao WEN, Peng ZHOU, and Yu-nong HU
Due to the characteristics of tunable bandgap, large electron effective mass, and low Auger recombination rate, type-II superlattices have unique advantages in long-wave and very long-wave infrared detection. The research progress in the preparation of long-wave superlattice detectors is introduced, including band struDue to the characteristics of tunable bandgap, large electron effective mass, and low Auger recombination rate, type-II superlattices have unique advantages in long-wave and very long-wave infrared detection. The research progress in the preparation of long-wave superlattice detectors is introduced, including band structure design, surface defects control, periodic structure control and surface passivation. Finally, a 320×256 long-wave superlattice focal plane array and its test performance are reported. The results show that at an operating temperature of 77 K, the cut-off wavelength of the array is 9.6m, the average peak detection rate D* is 7×1010 cm?Hz1/2/W, the noise equivalent temperature difference (NETD) is 34 mK, and the response non-uniformity is 7%..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 1 (2021)
Research on the Technology of 4 in HgCdTe on Silicon Substrate by Molecular Beam Epitaxy
Da GAO, Zhen LI, Cong WANG, Jing-Wei WANG, Ming LIU, and Ti NING
At present, the demand for large-format HgCdTe infrared focal plane array(IRFPA)detectors continues to increase, and the development of larger HgCdTe material technology has become a research hotspot. The 4 in silicon-based HgCdTe epitaxy technology is studied. Through a series of measures such as improving the stabiliAt present, the demand for large-format HgCdTe infrared focal plane array(IRFPA)detectors continues to increase, and the development of larger HgCdTe material technology has become a research hotspot. The 4 in silicon-based HgCdTe epitaxy technology is studied. Through a series of measures such as improving the stability of equipment parameters, controlling the flatness of epitaxial wafers, and optimizing material process parameters, the key technical bottleneck of the large-size silicon-based HgCdTe material process has been broken through. 4 in silicon-based HgCdTe materials with low flatness, high uniformity, low defect rate and high quality are obtained. The results show that the material′s full width at half maximum(FWHM)is not more than 90 arcsec, the surface macro defect density is not more than 100 cm-2, and the surface flatness is not more than 15 m..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 6 (2021)
Research on Purification of HgCdTe Material
Shu-kui SUN
Impurities are one of the important factors affecting the performance of HgCdTe devices. For CdZnTe substrate crystals and narrow bandgap HgCdTe materials, the impact of impurities is more significant. The common impurity types in HgCdTe materials and the role of impurities in the materials are mainly discussed. The maImpurities are one of the important factors affecting the performance of HgCdTe devices. For CdZnTe substrate crystals and narrow bandgap HgCdTe materials, the impact of impurities is more significant. The common impurity types in HgCdTe materials and the role of impurities in the materials are mainly discussed. The main impurities that affect the performance of the device are analyzed. Glow discharge mass spectrometry (GDMS) is used to test the impurity content in the material. At the same time, the impurity content in the CdZnTe substrate and the HgCdTe thin film material grown by liquid phase epitaxy is reduced through the improved zone melting process. The electrical performance of HgCdTe thin film is improved to meet the preparation requirements of high-performance HgCdTe infrared detectors..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 11 (2021)
Research on the Application of RTV566 Adhesive in Space Infrared Cryogenic Lens
Wei-ming TONG, Shao-jun BAI, Hui XING, and Yun-song NIE
In order to verify the application feasibility of RTV566 adhesive in space infrared cryogenic lens, the low temperature mechanical properties of RTV566 are tested, and the low temperature surface shapes of the experimental lens based on RTV566 are tested and studied. Firstly, RTV566 adhesive tensile test samples are deIn order to verify the application feasibility of RTV566 adhesive in space infrared cryogenic lens, the low temperature mechanical properties of RTV566 are tested, and the low temperature surface shapes of the experimental lens based on RTV566 are tested and studied. Firstly, RTV566 adhesive tensile test samples are designed and manufactured. And the bonding strength with germanium and titanium alloy，as well as the elastic modulus of the adhesive are obtained through static tensile test. Then the cryogenic lens test sample is designed and put into production. RTV566 adhesive is used to bond the lens into the frame, and a flexible structure is designed around the adhesive surface of the lens frame. The low temperature surface shapes of the lens are tested by ZYGO interferometer. The tensile test results show that the elastic modulus of the adhesive almost does not change from room temperature to 180 K, and the average value approximates to 6 MPa.The shear and tensile strength almost do not change from room temperature to 200 K, but increase at 180 K. The test results show that the surface shape of the lens almost does not change from room temperature to 200 K, whose accuracy is better than 1/30λ(λ=0.6328m).It indicates that the flexure structure and RTV566 adhesive reduce thermal stress, and ensure the surface shape of the lens. The research in this paper shows that RTV566 adhesive can be used in the support structure of space infrared cryogenic lens at 200 K and above..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 17 (2021)
Research on Reliability Improvement of Bellows J--T Cooler
Zhi-yong LIU, and Ji-fei YANG
As the important part of infrared detector component, bellows J-T coolers have been widely used. When used in the long-term vibration environment, the bellows as the self-control element will suffer from abnormal flow rate and failure of self-control. In order to improve the reliability of the cooler in the long-term vAs the important part of infrared detector component, bellows J-T coolers have been widely used. When used in the long-term vibration environment, the bellows as the self-control element will suffer from abnormal flow rate and failure of self-control. In order to improve the reliability of the cooler in the long-term vibration environment, the structure of the cooler is changed in this paper. The two-point support structure with diaphragm spring and PTFE guide ring is innovatively used which has a reliable radial support for the elastic moving parts of the cooler. It significantly improves the anti-vibration performance of the cooler, and has achieved good effect in practice. In addition, the research on the design in this paper also provides ideas for improving the anti-vibration performance of bellows J-T coolers in the future..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 25 (2021)
Theoretical Analysis and Experimental Study of Heat Loss of Stirling Cryocooler Regenerator
Guang-lei XIN, and Bo-wen REN
The regenerator is the core component of the Stirling cryocooler, which has a decisive influence on the performance of the Stirling cryocooler. The heat loss of the Stirling cryocooler (including finite heat transfer loss, pressure drop loss and empty volume loss, etc.) is analyzed theoretically, and the effect of incrThe regenerator is the core component of the Stirling cryocooler, which has a decisive influence on the performance of the Stirling cryocooler. The heat loss of the Stirling cryocooler (including finite heat transfer loss, pressure drop loss and empty volume loss, etc.) is analyzed theoretically, and the effect of increasing the number of meshes and different filling modes on the regenerator performance is also studied experimentally. The experimental results show that increasing the number of meshes can effectively improve the performance of cryocooler, and the mixed arrangement with 400 meshes at the cold end and a small amount of 100 meshes at the hot end has the best effect, which provides a basis for the performance optimization of Stirling cryocooler..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 31 (2021)
Research of Photoelectric Theodolite Measurement Method Without Landing
Bao-feng ZHANG
With the rapid development of the performance of the range observation targets, the performance requirements of the range observation equipment also show a trend of diversification, intelligence, high mobility, high precision and automation. In order to realize the photoelectric theodolite measurement scheme without laWith the rapid development of the performance of the range observation targets, the performance requirements of the range observation equipment also show a trend of diversification, intelligence, high mobility, high precision and automation. In order to realize the photoelectric theodolite measurement scheme without landing on the unfixed test ground, a fast mobile measurement platform without landing is designed, and its vibration parameters are measured in this paper. The experimental results show that the energy transferred from the servo system to the base is very small under the excitation of angular acceleration below 20°/s2 in the measurement mode without landing. The influence of motor excitation load on the platform can be ignored, and the resonance response occurs..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 3, 36 (2021)
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