Infrared Differential Detectors: A New Paradigm Beyond the Limits of BLIP
Infrared Differential Detectors: A New Paradigm Beyond the Limits of BLIP
Infrared Differential Detectors: A New Paradigm Beyond the Limits of BLIP
Infrared Differential Detectors: A New Paradigm Beyond the Limits of BLIP
Infrared Differential Detectors: A New Paradigm Beyond the Limits of BLIP
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DENG Rong, YUAN Hai-tao, SUN Xiao-jin, CHEN Fan-sheng, SUN Sheng-li, CHEN Zhong-ming
2025,46(7):1-11
Abstract:
Aiming at the requirements of lightweight and stiffness improvement of silicon carbide (SiC) plane mirror in the two-dimensional pointing mechanism of space camera, an innovative design scheme based on semi-closed backplate structure was proposed. By constructing a semi-closed topological configuration on the back and replacing the traditional open structure with it, the stiffness was improved by combining the control of the process hole size. The finite element model of the pointing mirror was established, and three design schemes were compared. The simulation results show that, under the premise of ensuring the surface shape accuracy index, the mass of scheme 2 was reduced from 12.8 kg to 10.7 kg (a decrease of 16.4%), the first-order natural frequency was increased from 730 Hz to 1528 Hz (an increase of 109%), and the stiffness-to-mass ratio was increased by 1.5 times. The performance index was significantly better than that of the traditional open structure (scheme 1) and the large aperture scheme (scheme 3). The optimized pointing mirror passed the sinusoidal vibration test, and the root mean square (RMS) value of the surface shape accuracy was doubled from 0.073λ to 0.036λ (λ=632.8 nm). The semi-closed backplane design proposed in this study breaks through the stiffness limitations of traditional lightweight structures and provides a new approach for the design of other space mirrors.
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2025,46(7):12-19
Abstract:
Aiming at the recognition difficulties of infrared small target detection caused by few pixels, weak texture and no color, an infrared small target detection algorithm for aerial unmanned aerial vehicle (UAV) is proposed. Based on multi-frame infrared sequences, the ResNet-50 network is used to extract deep features frame by frame, and the multi-scale deformable attention mechanism and cubic interpolation are combined to enhance the detail representation of small targets; the frame decoder and target decoder are designed to generate the spatiotemporal mask of the target instance through the video-level query vector. The Hungarian algorithm is used to optimize the classification, mask and similarity losses during training; the high-confidence query mask is fused during inference, and the inter-frame difference method is used to suppress static noise. On the DSAT dataset, the accuracy of the algorithm in this paper reaches 0.6356 and the F-score is 0.6475, and the performance is significantly improved. Through multi-scale feature fusion and temporal modeling, the algorithm effectively solves the problems of missed detection and false alarm of infrared small target detection algorithm, and provides a high-precision solution for UAV detection.
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WANG Dan, LI Zhen, JIANG Meng-jia, XING Wei-rong, GUAN Chong-shang
2025,46(7):20-25
Abstract:
In order to prepare high-quality mercury cadmium telluride (HgCdTe) materials with high reliability and controllable doping concentration, the properties of HgCdTe materials after As doping need to be studied. The As doping technology of silicon-based HgCdTe by molecular beam epitaxy (MBE) is reported. Using As cracking source as As doping source, high-quality HgCdTe materials are prepared, in which the As doping concentration can reach 8×1018 cm-3. The study found that As doping is very sensitive to material growth parameters such as growth temperature, As beam current, and material composition. By improving the growth temperature control and substrate heating method, the uniform distribution of As concentration in the horizontal and vertical directions of the material can be achieved. As activation annealing is carried out by a two-step annealing method. When the As concentration is lower than 3×1017 cm-3, the activation rate tends to 100%; with the increase of As doping concentration, the activation rate shows a downward trend.
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WANG Xiao-qian, LIU Ming, NI Yu-peng, LI Jing-feng, REN Ang
2025,46(7):26-31
Abstract:
Taking the deep mesa etching of medium- and long-wave two-color InAs/GaSb type-II superlattice infrared detector as the research background, the relationship between the photolithographic solid-film process and the quality of the deep mesa sidewall is analyzed. The influence of different solid-film temperatures on the graphic transfer effect of the mesa pattern and the quality of the mesa sidewall forming is studied, and the best solid-film process is obtained through optimization. The superlattice medium- and long-wave two-color photosensitive chip with smooth sidewalls is interconnected with the readout circuit and packaged into the dewar; it is cooled to 77 K by liquid nitrogen, and then the component test is carried out. The experimental results show that the medium- and long-wave two-color superlattice material uses AZ4620 photoresist as a pattern mask, and after a gradient temperature increase to 140 °C for solid-film, a mesa junction device with smooth sidewalls is obtained by dry etching. The module test results show that the smooth sidewall can effectively reduce the noise equivalent temperature difference (NETD), blind pixel rate and non-uniformity of the module.
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WANG Hui, FENG Xiao-yu, OUYANG Tian, MA Teng-da
2025,46(7):32-40
Abstract:
Indium bumps (i.e. indium balls) used in flip-chip interconnection technology are a material used to achieve electrical connection between chips and substrates in semiconductor packaging. If the indium columns are left for too long after wet shrinkage, oxides will form on the surface of the indium balls. Indium oxides can be quickly identified using a metallographic microscope. The influence of the presence of indium oxides on the pressure and conductivity of flip-chip interconnection is analyzed and discussed, and wet and dry methods are proposed to remove oxides. The parameters of the removal method are quantitatively studied, and the removal effect is tested and analyzed, making the research conclusions more comprehensive and complete. The results show that the detectors after flip-chip interconnection of the circuit with oxides removed by this method have relatively stable performance, laying a good foundation for the preparation of high-quality and high-reliability detectors.
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WEI Hong-miao, ZHANG Yu, LIU Ji-zhou
2025,46(7):41-48
Abstract:
The splicing of multiple videos on the display can not only monitor and view from a large viewing angle and various angles, but also solve the problems of messy display of multiple viewing angles in a single camera video and the inability to display the whole view due to target occlusion. A display with multi-channel infrared video splicing based on field programmable gate array (FPGA) is designed. The design of the display uses JFM7K325T-900 FPGA as the processor, and is equipped with two SCB15H1G160AF-15HI 16-bit synchronous dynamic random-access memory (SDRAM) as the image cache module. It supports serial digital interface (SDI) and high-definition multimedia interface (HDMI), and provides three high-speed digital video interfaces called flat panel display links (FPD-LINK). The three infrared video interfaces process three infrared video images with a resolution of 1280×1024 into three images with a resolution of 640×720 through FPGA to fill the display with a resolution of 1920×720. The results show that the display can display infrared images of different scenes in real time and complete multi-channel infrared video splicing.
Volume 46,2025 Issue 7
Articles
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Research on Design and Calibration of Terahertz source Based on Difference Frequency Generation
ZHU Jun-feng, ZHANG Gui-ming, ZHANG Ting, HU Xiao-ning, Wang Tong, LIU Ming, DU Zhi-qiang, JIANG Jin-chun
Abstract:
The difference-frequency module serves as the core component of the tunable terahertz source, with its performance directly determining the efficiency of terahertz generation. To enhance the terahertz output power, this study designed laser beam reduction systems with 2:1 and 3:1 ratios based on laser parameters after optical power amplification. This ensures consistent beam diameters for optimized spatial mode matching. Through polarization calibration, the lasers maintain linear horizontal polarization to fully exploit the crystal's maximum nonlinear coefficient. Post-alignment, the dual beams achieve precise spatial overlap, forming a focused spot of approximately 22 μm after passing through the focusing lens, thereby significantly enhancing difference-frequency conversion efficiency. Experimental verification confirms that this module has successfully enabled terahertz wave generation.
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A Stirling-cooled fast start Infrared Detector
Abstract:
The integrated Stirling-cooled infrared focal plane graphics component has the characteristics of small size, low power consumption, and high reliability, and is widely recognized in various infrared complete systems. However, existing detectors hardly satisfy the strict startup-time requirements of long-range missile weapon systems for guidance-based combat. This article analyzes the factors that affect the startup time of infrared focal plane detectors and proposes a new design concept. By designing a micro - Dewar and a refrigerator drive controller while keeping the original detector’s performance and the optical, mechanical, and electrical interfaces unchanged, rapid startup is achieved. Experimental results indicate that, under this condition, a considerable reduction in cool - down time has been obtained. The cool - down time can be reduced to within 3 minutes and 30 seconds at normal temperature. This significantly improves the detector’s fast cool-down capability and meets the project requirements.
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PM2.5 signal recognition and interpretable retrieval based on satellite infrared data
WANG Gen, YUAN Song, YE Song, FAN Chuan-yu
Abstract:
Particulate matter with a diameter less than 2.5 microns (PM2.5) on the ground has a negative impact on human health and the economy. Most methods obtain PM2.5 from satellite derived aerosol optical depth (AOD) indirect products or daytime atmospheric top reflectance. The purpose of this paper is to directly use the advanced geosynchronous radiation imager (AGRI) infrared data from Fengyun-4B satellite and artificial intelligence models to retrieve PM2.5 with spatial and temporal resolution of 4 kilometers and 15 minutes in the Yangtze-Huaihe region in near-real time throughout the entire time period (including day and night). Firstly, explore the signal response of AGRI brightness temperature to different levels of PM2.5 in different seasons; Secondly, a study on AGRI brightness temperature retrieval of PM2.5 was conducted based on the random forest method in different seasons. The experimental results showed that the PM2.5 correlation coefficients obtained from the seasonal retrieval were all over 0.87; Finally, based on SHapley Additive exPlanations (SHAP), the model was interpretable and the contribution of geographic information to PM2.5 was found to be significant. And further explored the application of the products mentioned in this paper.
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Study on the solution of atmospheric transmittance based on HO-RF
Abstract:
In order to improve the efficiency and accuracy of obtaining atmospheric transmittance parameters in infrared radiation test, this study proposes an atmospheric transmittance solution model based on HO-RF algorithm. The model takes the key environmental factors such as temperature, humidity, operating distance and atmospheric pressure as input, and establishes a regression solution model based on the measured data, so as to realize the rapid and accurate solution of atmospheric transmittance. The simulation results show that compared with the traditional BP neural network and RF model, the proposed HO-RF model performs better in terms of solution accuracy. The root mean square error ( RMSE ) is reduced to 0.010745, the R2 value is 0.95877, and the mean absolute error ( MAE ) is 0.0080021. The model proposed in this study can effectively reduce the complexity of experimental operation. Compared with the traditional method, it has higher accuracy, stability and reliability, and improves the efficiency of infrared characteristic test of fighter aircraft, which has good practical application value.
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An Intelligent Identification Method and Its Application for Downhole Fluid Types Based on Big Data in Near-infrared Spectroscopy
Kong Sun, Shen Yang, Yu Qiang, Chu Xiaodong, Bao Zhongli, Zuo Youxiang
Abstract:
Although COSL has successfully developed downhole optical spectrum analyzers, there are still shortcomings in interpretation, especially intelligent fluid identification driven by downhole spectral data in real time. In this paper, an intelligent fluid identification method driven by spectral data in real time is proposed for the first time. Firstly, based on a large number of measured spectral and fluid data, a database of various fluids is established. The spectral data and fluid types in the database are then preprocessed separately. The spectral data of 256 channels are further reduced by principal component analysis, and the first 10 principal components are chosen as input variables. Fluids are divided into 5 types (output variables): gas, oil, water, slurry (emulsified fluid, or invalid measurement), oil/gas-water mixture. Next, 23 pattern recognition models are used for modeling of fluid identification, including various trees, discriminants, support vector machines, K-nearest neighbor methods, artificial neural networks and so on. All the models are then analyzed and compared, and the best model is selected to be embedded in the formation test tool. The test accuracy of the 23 models after training is 78.1% - 99.9%. The artificial neural network is the best (accuracy of 99.9%). Finally, the spectral data from more than 40 sampling stations are employed to further examine the best model. The results show that the best model can accurately predict fluid types. The new intelligent identification method lays a solid foundation for eliminating the influence of water on the oil and gas spectra and analyzing the composition of oil and gas more accurately, thus reducing operation risks and saving operation time and costs.
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Study on the Frustum-shaped defects on the surface of HgCdTe film prepared by Liquid Phase Epitaxial growth
Yang Meihua, Xing Xiaoshuai, Yang Haiyan, Hu Yilin, Li Qian, Wang Lijun
Abstract:
In order to reduce the influence of the defects of telluride cadmium mercury (HgCdTe) thin films grown by liquid phase epitaxy (LPE) on the performance of infrared detectors, a special type of surface defects, the frustum-shaped defect, was systematically studied by means of scanning electron microscopy, energy dispersive X-ray spectrometer, focused ion beam and comparative experiments. The size of these defects ranges significantly, from approximately 150 to 400 micrometers, and under an optical microscope, they exhibit a morphology resembling a frustum with a concave center. Compositional analysis revealed no significant differences between the surface of the defect and the normal film morphology. Further analysis of the interface between the tellurium zinc cadium (CdZnTe) substrate and the HgCdTe film indicated that these penetrating defects orginate from triangular telluride inclusions with central holes on the CdZnTe substrate, and the size of tellurium inclusions is almost above 20 μm. Therefore, by improving the quality of the CdZnTe substrate and enhancing substrate screening, the frustum-shaped defects in HgCdTe films can be reduced, thereby improving the quality of HgCdTe epitaxial materials. This enhancement is essential to meet the demands of high-performance infrared detector development.
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A high operating temperature long wave mercury cadmium telluride detector with large charge handling capacityXing Yanlei Song Shufang
Abstract:
In recent years, the high operating temperature device with its light weight, small size, low heat consumption characteristics, while reducing the cost of the same level of performance as the low temperature detector advantages, gradually become the focus of infrared research. The large charge processing capability has the advantages of wide dynamic range (DR), high sensitivity, strong signal detection, etc., and is widely used in LiDAR, astronomical observation and other fields. In this paper, a long-wave mercury cadmium telluride detector with high charge processing capacity and operating at high temperature is introduced. The charge processing capacity can reach 40Me- at 15μm pixel spacing. The main performance of the device at different operating temperatures is compared and analyzed. At 110K, the effective pixel rate can reach 98.5%, the noise equivalent temperature difference is 28mK, and the peak quantum efficiency is 40%. Compared with the performance at 77K, it can still reach a good level.
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Progress of HgCdTe Mercury-Rich Vertical Liquid Phase Epitaxy in 11th Research Institute of CETC
HAO Fei, She Wei-lin, YANG Hai-yan, Hu Yi-lin, Xing Xiao-shuai, YANG Mei-hua, Xing Wei-rong, SUN Hao
Abstract:
In this paper, we focuse on the36mm×42mm mercury-rich vertical liquid phase epitaxy(VLPE) technique. By modifying the structure of the graphite boat carrying the substrates, the batch growth of large-size double heterojunction materials with dimensions of 36mm×42mm has been achieved. By combining the phase diagram of material growth and the calculated fluiddistribution, the fields of fluid and temperature in the growth area of the material are optimized to meet the development requirements of p-on-n infrared focal plane array detectors. The thickness deviation of the grown material and the electrical performance satisfies our expectation. The overall performance of the material meets the requirements for fabricating large-scale, large-format p-on-n infrared focal plane array detectors.
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ZHANG Min, HAN Fang, KANG Jian, SUN Hao, GUO Liang, LI Chun-ling
2019,40(6):35-43
Abstract:
The characteristics of infrared thermal imaging technology are introduced, and the civilian application of infrared thermal imaging technology in civil aviation, electric power, petrochemical, forest fire prevention, medical and other civil fields is discussed. The market situation of infrared thermal imaging technology is introduced, and the development demand of infrared thermal imaging technology in different application fields are analyzed.
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2008,29(8)
Abstract:
介绍了一种利用MATLAB和数值逼近理论计算费米函数的简捷方法.计算结果的误差在10-6数量级,甚至可以更高.与其他方法相比,该方法具有精度高、使用便捷和速度快等优点.
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2008,29(12)
Abstract:
In this paper,the principle and features of four-wave mixing are given.The generation of four-wave mixing is derived in theory and the applications of four-wave mixing in the DWDM for optical fiber communication,phase conjugation wave generation and real time optical detection are given.The study in this paper is aimed at more completely knowing the application direction of the four-wave mixing, a typical nonlinear optical effect and finding more applications for the four-wave mixing by summing up the existing relatively mature applications and research methods.
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Nie Jianhua, Liu Jiaqing, Meng Xin, Han Shunli
2019,40(6):44-48
Abstract:
In order to realize the reasonable classification of optical spectrometers, the classification study is carried out from the working band and spectroscope of the spectrometer. On the basis of in-depth research on the development status of existing spectrometer products at home and abroad, the related research is summarized and analyzed, and the specific classification methods and classification results are given. At the same time, by using known spectrometry technology and the research result, the comparative research conclusions of spectrometers are introduced, and the key technologies and core components are pointed out. This conclusion can provide spectrometer researchers with a panoramic viewing angle and also provide a valuable reference for tracking industry development.
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2010,31(3):42-46
Abstract:
According to the finite difference principle, a one-dimensional Schr\"{o}dinger equation can be converted into a set of nodal linear equations expressed in a matrix equation after the space is divided into a series of discrete nodes with an equal interval. The matrix left division command offered in the MATLAB software can be used to derive the function approximation of each unknown nodal function. This method is simple in concept, convenient in operation and can solve large linear equations without more efforts in programming.
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2019,40(7):35-46
Abstract:
The noise sources and denoising methods of functional near-infrared spectroscopy (fNIRS) brain imaging are reviewed. The method and operation of suppressing noise are analyzed and given from the aspects of imaging principle, noise source and occurrence mechanism. The composition and characteristics of the interference are analyzed in detail, the effective removal method is given, and the signal quality algorithm in the process of brain imaging analysis and modeling of near-infrared spectroscopy is improved. These methods can provide guidance for the analysis and processing of near-infrared spectroscopy brain imaging data. Three noise sources that affect near-infrared spectroscopy brain imaging signals are summarized: instrumental noise, experimental error and physiological interference from the body. Two practical denoising algorithms are given and the development trend of imaging technology is expounded.
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2008,29(12)
Abstract:
The good properties of THz wave and how to use photoconductive antenna and optical rectification to generate THz wave are described in detail.The applications of THz wave in long distance surveillance,imaging,exploder distinguishing,nondistructive inspection and particularly in the field of military are presented.
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GUO Xiao-Dong, ZUO Zhi-Gao, YUE Song, HONG Pu
2019,40(7):18-25
Abstract:
The theoretical model of infrared point target detection system is systematically analyzed. The transmittance of medium-wave and long-wave infrared light under typical atmospheric conditions is calculated by establishing the atmospheric stratification model and combining the MODTRAN model. The comparison data of the two calculation results can provide reference for the band selection in the design of infrared detection system. By analyzing the theoretical model of infrared radiation intensity of targets, the infrared radiation intensity of several typical targets in different wavebands is calculated, which provides support for the demonstration of operation range for IR system. Based on the probability density distribution function of infrared image noise, the theoretical formulas of image signal-to-noise ratio, system detection probability and false alarm probability are derived, which provide reference for setting detection threshold. The theoretical model analysis results of infrared point target detection system''s operation range can offer an important theoretical support for improving the credibility of infrared detection system''s operation range demonstration and the rationality of system parameter design.
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2010,31(3):11-14
Abstract:
The typhoon center is usually located manually by meteorologists. This location method has a low degree of automation. According to the movement characteristics of typhoon and the meteorological analysis theory, a single infrared satellite cloud image is used to establish a method for extracting the dominant cloud movement vectors. On this basis, the optimal target function for locating the typhoon center automatically is set and resolved. The automatical location of the typhoon with an eye or without an eye is realized. The method is used to simulate the automatical location of the center of typhoon ``HAITANG' in several cloud images obtained in 2005. The result shows that this method has a high location accuracy and can be used as a good technical means for the automatical location of typhoon center.
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2019,40(6):27-34
Abstract:
From the perspective of theoretical numerical simulation and near-field radiation experimental research, the latest research results in near-field thermal radiation heat transfer are introduced. The focus of theoretical research is mainly on heat transfer studies in graphene composites, artificial processing and synthetic metamaterials. The focus of experimental research is on laboratory equipment manufacturing and method innovation based on nanoscale near-field thermal radiation measurements. Very near-field thermal radiation measurements with a minimum distance of only 2 nm have been experimentally implemented. Further research on near-field thermal radiation provides a theoretical basis for thermal photovoltaic, radiant cooling and efficient energy harvesting applications.
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wngxinkun, zhaofang, wangjianjiang
2019,40(7):1-11
Abstract:
With the advent of various new types of detection radars, advanced infrared detectors and precision guided weapons, infrared & radar compatible stealth materials have become the focus of current stealth technology research. The stealth principle and research status of traditional and new infrared & radar compatible stealth materials are reviewed, and the development direction of future infrared & radar compatible stealth materials is summarized and forecasted.
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2013,34(7):15-19
Abstract:
Starting from the Schrodinger equation, the influence of different Al composition and different temperatures on the absorption spectra of wide quantum well infrared photodetectors (QWIP) is studied. It is found that when the Fermi level is fixed, the ground state bound energy of the quantum well may increase with the increasing of the Al composition and the corresponding absorption spectral peak tends to move toward the short wave. In addition, the influence of the ambient temperature on the response spectra of AlGaAs/GaAs QWIPs is negligible. After theoretical calculation, the rule of the absorption spectrum of an AlGaAs/GaAs QWIP changing with quantum well width, Al composition and temperature is given.
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2008,29(12)
Abstract:
第一部分 一、探测与识别 1.高光谱图像的结构模型中正交子空间投影探测器与匹配滤光片的分析比较(P.Bajorski,美国罗彻斯特理工学院)
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Gao Yuxuan, Chen Xingming, Dai Jun, Yang Meixia, Huang Shoubin, Chen Xiang, Hou Zhenyan, Huang Jian
2023,44(4):20-32
Abstract:
Focusing is a key part of the launch focusing device in highenergy laser systems, and the focusing mechanism plays an important role in the targeting and striking accuracy of the system. In order to understand the research status and development trend of focusing mechanism, various types of foreign mature focusing mechanisms are introduced firstly. The principle of their focusing control and the solutions of various technical problems are analyzed. The domestic research situation focuses on four types of focusing mechanisms: cam, screw, worm gear and direct drive. For each form of focusing mechanism, the basic principle of controlling focusing is analyzed, and the design features of the focusing mechanism applied to different systems are introduced. By analyzing the design and control of each type of focusing mechanism, the advantages and disadvantages are summarized and compared, and the design ideas and research directions of the focusing mechanism for high-energy laser systems are proposed to lay the technical foundation for the research on focusing mechanism of high-energy laser systems.
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2008,29(8)
Abstract:
本文研究由介电系数和磁导率为负的材料组成的一维光子晶体中的电磁波脉冲的传播特性.利用传输矩阵的方法,计算出了该结构中脉冲传播的透射谱和相时间.数值结果表明,在光子带隙的带边和带底会分别出现脉冲传播速度减慢和加快的现象.若周期结构中间存在缺陷层,光子带隙中会出现极窄的透射峰,因此,对应于该频率的电磁波在该体系中传播时速度会变得更加缓慢.
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PAN Ming-zhong, QI Hong-xing, XIAO Gong-hai, SHU Rong
2010,31(1):1-7
Abstract:
A compact field hyperspectral imaging spectrometer based on a prism-grating-prism structure is presented. The system is designed for the wavelength range from visible light to near infrared. It has 344 spectral bands with the spatial resolution higher than 10 nm and the spectral resolution higher than 1 mrad. To study the unmixing of mixed pixels, the basic principle of the field hyperspectral imaging spectrometer is described, the main specifications of the system is analyzed, the design of the system is discussed in detail and related tests are conducted. The test results show that the system has both higher spatial resolution and higher spectral resolution. Because of its compactness and reliable operation, it is very suitable for field applications. Thus, the feasibility of the use of a compact field hyperspectral imaging spectrometer in the research on the unmixing of mixed pixels is verified.
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2011,32(8):25-28
Abstract:
Sea-sky-line detection can be implemented by effectively suppressing the background and enhancing the target in an image according to the features of sea-sky environment. An improved method for wiping off crass points is proposed on the basis of the linear fitting algorithm. The method is simulated with the Matlab software. The simulation result shows that this improved method can effectively detect the positions of the sea-sky-line and ships against the sea-sky background. It provides a good basis for target recognition and image registration.
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WUWEI, HANSHUNLI, HOUXIBAO, LIULEI, XIANGGUOQING
2017,38(6):1-7
Abstract:
According to the spectral response curves and dark current of a near infrared two-dolor detector in two different operation wavebands, a signal acquisition system based on the near infrared two-color detector is designed. The system has many current-voltage conversion levels, voltage amplification levels and filter circuit bandwidth levels. It can amplify signals and control bandwidth quickly. Moreover, it provides zero analog signals for four amplify circuits via a Digital-to-Analog (D/A) convertor. This can effectively eliminate the noises caused by the stray light and the dark current of the detector itself. The system has the features of high speed, low noise and high resolution. By using this signal acquisition system, many parameters of the optical system, such as signal-to-noise ratio, dynamic range and minimum measurable power, can be improved.
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2016,37(4):27-32
Abstract:
An algorithm combining Light of Sight (LOS) with the OpenGL software interface is proposed. The method uses the depth measuring and occlusion query functions of the OpenGL software interface to determine the effective emission surface in the detection direction and the transfer path of its radiation in mediums. Then, it uses LOS to obtain the radiation characteristics of the target in atmosphere in the detection direction. The simulation result shows that this algorithm is effective and has high computation efficiency.
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BAI Wei, ZHAO Chao, GONG Zhi-hong
2017,38(1):6-11
Abstract:
Combining with the X-ray diffraction technique and the layer-by-layer chemical etch method for peeling damage layers, the depth of the damage layer in InSb crystal introduced by cutting, lapping and polishing was analyzed quantitatively. The structures and causes of damage layers were discussed. The research result showed that cutting was the major process for introducing damage layer on the surface of InSb wafers. The depth of the damage layer introduced by cutting was up to 16 microns. The depth of the damage layer introduced by double-face lapping was about 12 microns. The depth of the damage layer introduced by mechanical-chemical polishing obviously decreased. It was about 2 microns.
