Volume 41,2022 Issue 1

40th anniversary

• Recent hotspots and innovative trends of infrared photon detectors

  YE Zhen-Hua, LI Hui-Hao, WANG Jin-Dong, CHEN Xing, SUN Chang-Hong, LIAO Qing-Jun, ZHOU Song-Min, LIN Jia-Mu, HUANG Ai-Bo, LI Hui, PAN Jian-Zhen, WANG Chen-Fei, CHEN Hong-Lei, CHEN Lu, WEI Yan-Feng, LIN Chun, HU Xiao-Ning, DING Rui-Jun, CHEN Jian-Xin, HE Li

  2022,41(1):1-25, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Abstract:

  Infrared photon detection technology usually works in the passive sensing mode and contains the advantages of long acting-distance， good anti-interference， excellent penetration of smoke and haze， and all-day operation， which has been widely used in space remote sensing， military equipment， astronomical detection and other aspects. So far， the second-generation and the third-generation infrared photon detectors have been deployed widely. The high-end third-generation infrared photon detectors have been gradually promoted to practical application. The fourth generation and more forward-looking research including new concept， new technology， and new device has been proposed. This paper focuses on the research status of infrared technology at home and abroad， emphatically introducing the hotspots and development trends of infrared photon detectors. Firstly， the concept of SWaP³ is introduced due to tactical ubiquity and strategic high performance. Secondly， the high-end third-generation infrared photon detectors with ultra-high spatial resolution， ultra-high energy resolution， ultra-high time resolution and ultra-high spectral resolution are reviewed. Technical characteristics and implementation methods of ultimate-performance infrared detectors are analyzed. Then， the fourth-generation infrared photon detector based on the artificial micro-structure is discussed. The realization approaches and technical challenges of multi-dimensional information fusion such as polarization， spectrum and phase are mainly introduced. Lastly， highly innovative trends of future detectors are discussed according to upgradation from on-chip digitization to on-chip intelligence.

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• Progress on nBn infrared detectors

  Shi Qian, Zhang Shukui, Wang Jianlu, Chu Junhao

  2022,41(1):26-37, DOI:

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  The nBn infrared （IR） detector is designed to eliminate the Shockley-Read-Hall （SRH） generation-recombination （G-R） currents， which will effectively reduce the dark current and increase the operating temperature of the detector. Due to the compatibility of the manufacturing process and the existence of a substrate with a perfectly matched lattice， the nBn infrared detectors based on III-V compounds including type-II superlattice （T2SLs） materials have been developed rapidly. Through theoretical simulation， the nBn infrared detector based on the HgCdTe material system can also effectively suppress the dark current. However， the difficulty of removing the valence band barrier hinders HgCdTe nBn infrared detector development. This review will elaborate on the physical mechanism of nBn detectors to suppress dark current， and then introduce the development status and development trend of nBn barrier detectors in different semiconductor materials.

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• Infrared photodetectors for multidimensional optical information acquisition

  Guo Jiaxiang, Xie Runzhang, Wang Peng, Zhang Tao, Zhang Kun, Wang Hailu, He Ting, Li Qing, Wang Fang, Chen Xiaoshuang, Lu Wei, Hu Weida

  2022,41(1):38-58, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  The infrared photodetector can obtain IR radiation either reflected by or radiated from the target， which is a unique property and makes infrared photodetectors play an important role in areas such as national defense， communications， remote sensing， and aerospace along with other advantages， such as strong anti-interference， full-time detection， long detection range， and high-resolution imaging. The infrared photodetector is undergoing radical development from the application of the first generation multielement detectors in the 1940s to the striving for the proposal of SWaP³ concepts in the third generation in the late 1990s. Traditional infrared photodetectors， of which the advancement focus on improving performance indicators such as array size， sensitivity， and resolution， using light intensity information for imaging， are sluggish to meet future demanding such as recognizing diverse targets， facing environmental complexity， and dealing with multiform tasks at the same time. Infrared photodetectors for multidimensional optical information acquisition provide new routes to improve the device performance and meet future needs. Infrared photodetector obtains not only abundant intrinsic information of light besides intensity， such as phase， wavelength， polarization， and momentum， but also external information like optical path. This paper focuses on the multi-dimension infrared detection extracting information of wavelength， polarization， phase， and the optical path of the targets， which does not only summarize the research progress of infrared photodetectors from the aspects of new principles， new materials， and new structures， but also put forward the idea and outlook for the development direction of the multi-dimensional infrared photodetectors.

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• Research and application of spectroscopic techniques in lunar and Mars exploration missions

  Gui Yuhua, LI Jin-Ning, WANG Mei-Zhu, HE Zhi-Ping

  2022,41(1):59-69, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Spectral instruments have the ability to acquire spectral information and images for targets， and can realize nondestructive identification and quantitative interpretation of the mineral composition， which has become the key scientific payloads in lunar and Mars exploration missions， and provides an important basis for the study in aspects of surface composition and mineral resources， formation and evolution history and resource utilization. This paper briefly illustrates the research progress and application status of spectroscopic technology in lunar and Mars exploration missions at the domestic and international level in recent years. The seven spectral instruments and their application status in China’s Lunar Exploration Program （CLEP） and Tianwen-1 mission are summarized. In addition， this paper further introduces the typical scientific outputs for lunar and Martian spectral data. Finally， the application prospect and development trend of spectral instruments in the field of lunar and deep space exploration are discussed.

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• Recent advances in short wavelength infrared InGaAs focal plane arrays

  LI Xue, GONG Hai-Mei, SHAO Xiu-Mei, Li Tao, Huang Song-Lei, MA Ying-Jie, Gu Yi, Fang Jia-Xiong

  2022,41(1):70-79, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Abstract:

  To meet with the ongoing demand for the development of higher performance space remote sensing instruments， a series of progress in short wavelength infrared InGaAs focal plane arrays （FPAs） has been achieved in Shanghai Institute of Technical Physics. Through the continuous research efforts devoted to the low-defect density epitaxial materials， the FPA processing technologies as well as the low noise read-out circuits， a 10-μm-pitch 1~1.7 μm InGaAs FPA with an array format up to 2560×2048， a pixel operability up to 99.7% and a high peak detectivity up to 1.1×10¹³ cmHz^1/2/W is realized. A 15-μm-pitch 1~2.5 μm extended wavelength InGaAs FPA with an array format of 1280×1024 and a high peak detectivity up to 5.0×10¹¹ cmHz^1/2/W is also achieved. New principle FPA detectors are also developed， which are a monolithic integrated four-direction polarized 160×128 InGaAs FPA with a high extinction ratio up to 37：1， and a 64×64 InGaAs Geiger-mode avalanche FPA with a fine timing resolution down to 0.8 ns.

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• Research on terahertz quantum well photodetector

  ZHANG Zhen-Zhen, FU Zhang-Long, WANG Chang, CAO Jun-Cheng

  2022,41(1):80-86, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Terahertz quantum well photodetectors （THz QWPs） are ultra-fast devices， which have picosecond response time and more than 1 GHz modulation speed. THz QWPs have great potential applications in the field of THz fast imaging and high-speed wireless communications. This paper summarizes the principle， design， performance and recent research progress of THz QWPs. Research shows that the fast imaging system based on THz QWPs can detect the detailed information of the object， which is expected to be used in the field of safety inspection and nondestructive testing. Additionally， THz QWPs can be used as the detection end of high-speed wireless communication， providing an effective technical approach for future 6G wireless communications.

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• The research progress of vacuum electron device in terahertz band

  CHANG Shao-Jie, WU Zhen-Hua, HUANG Jie, ZHAO Tao, LIU Di-Wei, HU Min, WEI Yan-Yu, GONG Yu-Bin, LIU Sheng-Gang

  2022,41(1):87-104, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  The terahertz wave has great potential in deep space exploration， nondestructive testing， communication and security inspection because of its characteristics of electronics and photonics. The rapid development of terahertz technology in recent years is inseparable from the continuous progress of terahertz vacuum electronic devices. Due to the size sharing effect and the limitation of electron beam emission performance， this type of device has encountered considerable difficulty in the process of higher frequency bands. To solve these problems， a series of measures have been taken， such as improving high-frequency structure， controlling machining accuracy， preparing materials with better performance and more accurate calculation methods. This paper introduces the solutions and the latest progress of several mainstream miniaturized terahertz devices， and finally summarizes the problems and solutions that may be encountered in the future according to the current development situation.

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• Research progress of free-electron radiation based on metamaterials

  ZHU Juan-Feng, DU Chao-Hai

  2022,41(1):105-117, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Various types of electromagnetic radiation can be stimulated by free electrons interact with the local electromagnetic environment. Metamaterial is a kind of artificial material， which can achieve unique characteristics that natural material cannot realize. Based on the interaction between the metamaterial and free electron， the radiation characteristics can be flexibly manipulated such as polarization， phase and wavefront， and so on. The related study provides a novel platform for developing novel free-electron radiation devices. This paper briefly introduces the physical mechanism of Cherenkov radiation and Smith-Purcell radiation. Then， the state-of-art of free-electron radiation in metamaterials is introduced. Finally， an outlook of potential research directions for this vigorous realm is provided.

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• Subwavelength thin-film stack metamaterials： theory and applications

  WEN Zheng-Ji, LI Xiao-Wen, ZHAO Wen-Chao, SUN Yan, HAO Jia-Ming, DAI Ning, CHU Jun-Hao

  2022,41(1):118-135, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Subwavelength thin-film stack metamaterials， as a special group of metamaterials， have attracted much attention owing to their subwavelength thickness， ease of fabrication， low-cost and large-area fabrication capacities， etc. In this article， the recent research progress of the theory and applications based on subwavelength thin-film stack metamaterials is reviewed. We first focus on the overview of the theoretical background and the newly developed techniques for subwavelength thin-film stack metamaterials. Then， we highlight the progress of recent applications， including structural colors， photoluminescence （PL） enhancement， thermal emitter and infrared stealth， etc. Finally， the future opportunities and challenges about further research on the subwavelength thin-film stack metamaterials are also addressed.

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• Interband cascaded infrared optoelectronic devices for high operating temperature applications

  CHAI Xu-Liang, ZHOU Yi, WANG Fang-Fang, XU Zhi-Cheng, LIANG Zhao-Ming, ZHU Yi-Hong, ZHOU Jian, ZHENG Lu-Lu, HUANG Min, BAI Zhi-Zhong, HUANG Ai-Bo, CHEN Hong-Lei, DING Rui-Jun, CHEN Jian-Xin

  2022,41(1):136-142, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  High operating temperature infrared detector is one of the important development tendencies for the third-generation infrared focal plane. The interband cascade photodetectors take advantage of potential barrier structure and multistage absorption structure. Unidirectional transport of photogenerated carriers is achieved through relaxation and tunneling region which can reduce the generation-recombination current from the depletion region of the PN junction. The interband cascade detectors can effectively collect photo-generated carriers， and even the diffusion length is short utilizing the multiple and short absorption regions. So the detection performance can be improved at high operating temperature. In this paper， we present our recent research progress in the interband cascaded infrared optoelectronic devices， including high operation temperature infrared interband cascade detectors， high speed interband cascade detectors， and interband cascade light-emitting devices.

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• Recent progress of airborne infrared remote sensing technology in SITP

  WANG Chong-Ru, YANG Li-Feng, CAO Xun, WANG Yue-Ming

  2022,41(1):143-154, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Airborne infrared remote sensing technology has irreplaceable advantages， such as full-time work， flexibility and high spatial resolution， etc. It plays a key role in remote sensing science， land monitoring， national defense applications， etc. Development of airborne infrared remote sensing is vital to our country's national defense and economic development. In recent years， airborne infrared remote sensing technology has developed rapidly， with crucial breakthroughs in high spectral resolution infrared imaging and high spatial resolution infrared imaging. To get higher spatial resolution， spectral resolution， temporal resolution and radiometric resolution are missions of infrared technology research group. While introducing the latest international developments， the paper presents significant technological breakthroughs made by the Shanghai Institute of Technical Physics airborne remote sensing team in full-spectrum hyperspectral imaging and area-array scanning imaging. New generation instruments have been successfully applied to land classification， thermal drainage monitoring of nuclear power plants and other application fields. The latest results are given.

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• In-orbit geometric imaging simulation based on ray-tracing for long-linear-array and whisk-broom thermal infrared imager

  LI Xiao-Yan, HU Zhuo-Yue, JIANG Lin-Yi, CHEN Fan-Sheng

  2022,41(1):155-165, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  In order to solve the problems of image quality evaluation， imaging link analysis and subsequent processing algorithm verification due to the lack of in-orbit data before satellite launch， an in-orbit geometric imaging simulation method for long-linear-array and whisk-broom （LLAWB） thermal infrared imager （TIRI） based on ray tracing is proposed. Firstly， according to the structure and imaging characteristics of the optical system， the rigorous geometric imaging model of the LLAWB TIRI is constructed. Then， based on the simulation attitude and orbit parameters， auxiliary DOM and DEM data， the spatial projection and imaging simulation of pixel visual vector are realized by ray tracing and re-projection algorithm. Finally， a geometric calibration method based on "generalized" correction matrix is proposed to modify the positioning model and improve the positioning accuracy of simulation images. Experimental results show that the proposed method can be used to simulate the geometric imaging of any orbit position for the LLAWB TIRI， and the positioning accuracy of the simulation image is better than two pixels after calibration. This research provides a new idea for in-orbit geometric imaging simulation of space optical payloads， and is of great significance to the error analysis， geometric positioning and calibration of imaging links.

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• The fluorescence in vivo wide-field microscopic imaging technology and application in the second near-infrared region

  QUE Bu-Jun, PENG Shi-Yi, GENG Wei-Hang, CUI Jian, HU Sen-Hu, FENG Zhe, QIAN Jun

  2022,41(1):166-183, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  The wide-field fluorescence microscopic imaging in the second near-infrared region （NIR-II， 900-1880 nm） is currently a hot spot for deep in vivo bioimaging， with great potential in both basic research and clinical applications. Compared to the visible （Vis， 360-760 nm） and the first near-infrared （NIR-I， 760-900 nm） region， NIR-II fluorescence in vivo wide-field microscopic imaging provides higher spatial resolution and deeper tissue penetration. On the basis of NIR-II macroscopic imaging， the demand for deciphering of tissue microstructure forces the continuous development of fluorescent agents and the imaging system. NIR-II wide-field microscopic imaging technology has achieved a series of breakthroughs in biological applications such as accurate vascular microscopy， tumor analysis and accurate inflammation tracking. The research objects include rodents （such as mice and rats） and non-human primates （such as marmosets and macaques）. With the breakthrough of instrument commercialization and localization as well as the increasing biocompatibility of fluorescent probes in the future， the application values of NIR-II fluorescence wide-field microscopic imaging will continue to upsurge. This article discusses the mechanism and advantages of NIR-II imaging first，and then， reviews the characteristics and history of NIR-II fluorescence wide-field microscopic imaging， as well as its latest exploration and prospects for in vivo imaging on different biological models. The purpose is to promote the further popularization of NIR-II fluorescence in vivo wide-field microscopic imaging.

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• Photonic and electric control in terahertz quantum cascade lasers： Review

  HUANG Jia-Hao, XU Gang-Yi

  2022,41(1):184-195, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  As one of the most effective methods to generate terahertz laser， how to improve the performance of terahertz quantum cascade laser has been the focus of the scientific community. In this review， the current performance of terahertz quantum cascade lasers is described from the perspective of photonic and electric control. Starting from the principle of active region design of laser， several new active region designs are introduced， and then a series of new structures are introduced from the perspective of resonator， and their improvement on power and beam quality is shown. Finally， we describe the recent progress in polarization regulation and frequency tuning of terahertz quantum cascade lasers.

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• The application of terahertz technology in paintings

  YANG Jing, QIU Jie-Fu, JIANG Hui, HU Min, LIU Sheng-Gang, ZHANG Hui

  2022,41(1):196-207, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Over the last several years， Terahertz spectroscopy has been used in different fields， including archaeology and cultural heritage conservation. This paper presents a review of the terahertz technology applied to paintings， focusing on THz-TDS （terahertz time domain spectroscopy） in pigment identification， terahertz imaging technology in fresco and oil painting study. Some other new technologies are also discussed.

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• 3D-printed conformal metasurface invisibility cloak with arbitrary boundary

  WANG Chao-Hui, XU He-Xiu, PANG Zhi-Chao, WANG Ming-Zhao, WANG Shao-Jie

  2022,41(1):208-215, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Metasurfaces have intrigued great interest among researchers in electromagnetic （EM） engineering field due to the powerful ability of EM manipulation and advantages of low loss， low profile and ease-fabrication. Nevertheless， due to the limitation of the fabrication technology， currently， most of the reported metasurface carpet invisibility cloaks are composed of two-dimensional planar structures. It is still a challenge to achieve conformal metasurface carpet invisibility cloak for an object with arbitrary boundary. Therefore， we designed and demonstrated a conformal metasurface carpet invisibility cloak with arbitrary boundary based on metasurfaces and 3D-printed technology， which breaks the limitation of two-dimensional planar structures and achieves radar stealth for ground object. Both simulated and measured results show that such conformal metasurface invisibility cloak exhibits an excellent stealth performance and sustains performance stability at certain incident angles. Notably， the proposed 3D conformal metasurface invisibility cloak not only promises a wide application prospect in the EM stealth field， but also opens a new way to design EM devices.

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Infrared Materials and Devices

• InAs quantum wells grown on GaP/Si substrate with Ga(In,As)P metamorphic buffers

  HUANG Wei-Guo, GU Yi, JIN Yu-Hang, LIU Bo-Wen, GONG Qian, HUANG Hua, WANG Shu-Min, MA Ying-Jie, ZHANG Yong-Gang

  2022,41(1):216-224, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  InAs/In_0.83Al_0.17As quantum wells have been demonstrated on In_0.83Al_0.17As metamorphic layers on GaP/Si substrates. The effects of Ga_xIn_1-xP and GaAs_yP_1-y graded buffer layers on the sample performances are investigated. The sample with Ga_xIn_1-xP metamorphic buffer layer has narrower width in X-ray diffraction reciprocal space maps， indicating less misfit dislocations in the sample. Mid-infrared photoluminescence signals have been observed for both samples at room temperature， while the sample with Ga_xIn_1-xP metamorphic buffer shows stronger photoluminescence intensity at all temperatures. The results indicate the metamorphic buffers with mixed cations show superior effects for the mid-infrared InAs quantum wells on GaP/Si composite substrates.

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• SCM study on the 2D diffusion behavior of p-type impurities in planar InGaAs detectors

  ZHANG Shuai-Jun, LI Tian-Xin, WANG Wen-Jing, LI Ju-Zhu, SHAO Xiu-Mei, LI Xue, ZHENG Shi-You, PANG Yue-Peng, XIA Hui

  2022,41(1):225-231, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Scanning Capacitance Microscopy （SCM） was applied to obtain the 2-dimensional carrier distribution on the cross-section of planar type InGaAs/InAlAs pixels. The profile of pn junction in the device structure was able to be depicted with high space resolution. Besides， for InGaAs/InP detector， the SCM study helps to disclose the distinct diffusion behavior of p-type impurities in different functional layers. The lateral diffusion speed of zinc in InGaAs absorption layer was decided as 3.3 times than that in the depth direction， which is significantly higher than the lateral to depth ratio of 0.67 in the n-InP cap layer， this could affect both the capacitance and dark current properties of the diode pixels.

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• Design of a diagonally symmetrical photonic crystal fiber for chemical sensing

  ZHAO Li-Juan, ZHAO Hai-Ying, XU Zhi-Niu, LIANG Ruo-Yu

  2022,41(1):232-241, DOI:

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  A novel photonic crystal fiber with high birefringence and low confinement loss is designed， which can be used for chemical sensing . The effects of air holes parameters on optical properties of optical fiber are systematically investigated. The results reveal that the relative sensitivities of the fiber with the optimal structure for water， ethanol and benzene at the wavelength of 1.55 μm are 56.3%， 59.9% and 62.5%， respectively. Compared with the existing PCFs， they are improved by 1.05-6.25 times， 1.05-4.99 times and 1.03-4.63 times， respectively. Besides， it has excellent transmission characteristics. Therefore， the proposed photonic crystal fiber has advantages in chemical sensing and biomedicine filed.

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• Influence of oxygen partial pressure on the optical properties of β-Ga₂O_3-δ films deposited by pulsed laser deposition

  LI Liu-Meng, ZHOU Bin, GAO Li-Chen, JIANG Kai, ZHU Liang-Qing, ZHANG Jin-Zhong, HU Zhi-Gao, CHU Jun-Hao

  2022,41(1):242-247, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  High quality β-Ga₂O_3-δ films on c-sapphire substrates are deposited by pulsed laser deposition （PLD） under various oxygen partial pressures. The crystalline structure， chemometry and optical properties of the β-Ga₂O_3-δ films are investigated systematically by X-ray diffraction （XRD）， far-infrared reflectance spectra， X-ray photoelectron spectroscopy （XPS） and ultraviolet-visible-near infrared （UV-vis-NIR） transmittance spectra. The XRD analysis shows that all the as-deposited films are of unique （-201） orientation. The transmittance spectra reveal that the films exhibit a high transparency above 80% in the UV-vis-NIR wavelength region above 255 nm （4.863 eV）. Moreover， the optical constants and optical direct bandgap are extracted based on the transmittance spectra with Tauc-Lorentz （TL） dispersion function model and Tauc’s relationship， respectively. A further step， the influence of oxygen partial pressure on optical properties is explained by theoretical calculation.

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Terahertz and Millimeter Wave Technology

• Design of millimeter-wave detectors based on zero-bias Schottky diode for direct detection system of CubeSat radiometer

  CHEN Yao, ZHANG Sheng-Wei

  2022,41(1):248-256, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Abstract:

  In this paper， two millimeter-wave zero-bias Schottky detectors for the direct detection system of the CubeSat radiometer， with center frequencies of 89 GHz and 150 GHz， respectively， were designed and implemented. These designs were based on zero-bias Schottky diodes of ACST. A radial stub structure was adopted at the DC ground and output port with a tuning line for optimum impedance matching to achieve stable and high performance and broadband characteristics； this structure also makes the circuit easier to integrate with pre-level systems and more suitable for CubeSat radiometer miniaturization. Circuit structure and Schottky diode were analyzed， modeled， and optimized to obtain better performance. The results showed that the W-band detector has a typical sensitivity of about 2500 V/W in the range of 85 GHz to 95 GHz and a linearity of 0.9994 at 89 GHz. Moreover， the D-band detector has a typical sensitivity of about 1600 V/W in the range of 145 GHz to 155 GHz and a linearity of 0.9992 at 150 GHz. These results verified the advantages of the improved circuit structure in the detector and the feasibility of the direct detection system.

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• A millimeter-wave fast imaging algorithm with range compensation for one-stationary bistatic SAR

  CHEN Xu, YANG Qi, ZENG Yang, WANG Hong-Qiang, DENG Bin

  2022,41(1):257-261, DOI:

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  In this article， an improved millimeter-wave fast imaging algorithm with range compensation for one-stationary bistatic synthetic aperture radar （OS-BiSAR） is presented. During the process of image reconstruction， the amplitude attenuation factor of the echo model is retained for the compensation of signal propagation loss， and the convolution operation is performed on the receiving array dimension according to the characteristics of the target echo equation. Finally， the target image can be solved by fast Fourier transform （FFT） and coherent accumulation steps. Simulation analysis and experimental results show that， compared to the range migration algorithm （RMA） with range compensation， the proposed algorithm can not only guarantee the efficiency of image reconstruction， but also significantly reduce the influence of signal propagation loss on the image quality.

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• Miniaturized 60-GHz transformer-based balun splitter with isolation and matching performance in 0.18-μm SiGe BiCMOS

  ZHANG Da-Wei, XU Xin, LI Bin, XU Hui, YU Hong-Xi, LI Jun, MA Kai-Xue, THANGARASU Bharatha Kumar, YEO Kiat Seng

  2022,41(1):262-267, DOI:

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  This paper presents the work of a miniaturized 60-GHz balun chip with isolation and matching performance fabricated in 0.18-μm SiGe BiCMOS process. The use of isolation circuit as key building blocks within a 60-GHz transformer balun leads to an improved isolation performance between output ports， while simultaneously achieving the matching performance of them. Moreover， compared to the conventional isolation circuit， the artificial left-handed transmission line is introduced to remove the bulky distributed elements， and the capacitive loading compensation technique is utilized for both matching and miniaturization. Both electromagnetic simulation and measurement results of the proposed 60-GHz transformer balun chip design with isolation and matching characteristics are given with good agreement. From measurement results， better than 25-dB isolation and 18-dB return loss of the output ports have been achieved at 60 GHz， with an occupied area of 0.022 mm².

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• W-band dual-sheet beam traveling-wave tube with a novel planar slow-wave structure

  DONG Yang, GUO Jing-Yu, WANG He-Xin, WANG Zhan-Liang, LU Zhi-Gang, GONG Hua-Rong, DUAN Zhao-Yun, GONG Yu-Bin, WANG Shao-Meng

  2022,41(1):268-273, DOI:

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  A dual-beam rectangular ring-bar （DBRRB） slow wave structure （SWS）， which is with a planar structure and is suitable for micro fabrication， is proposed for W-band traveling-wave tubes （TWT）. Supported by a pair of T-shaped dielectric rods， the RRB SWS is fit for dual-sheet beam operation. The high frequency characteristics are analyzed by using computer simulations. Wide bandwidth input-output structures adopting tapered structure and step waveguide are designed. Hot-test performance of the RRB SWS is investigated by means of Particle-in-cell （PIC） simulations. A solenoid magnetic field of 0.6 T is adopted to focus the sheet beams with voltage and current of 11.2 kV and 0.12 A. The saturated output power of 56.7 W at 94 GHz is obtained at the output port， corresponding a gain of 27.4 dB. In addition， an attenuator is added to suppress oscillations and achieve stable operation.

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• Design, fabrication and cold test of a high efficiency folded groove waveguide for w-band sheet beam TWT

  TIAN Yan-Yan, WANG He-Xin, SHI Xian-Bao, LI Xin-Yi, GONG Yu-Bin, HE Wen-Long

  2022,41(1):274-279, DOI:

  Abstract: (0) HTML (0) PDF (2.42 MKB)(0)

  Abstract:

  In this paper， a design， fabrication and cold test of a high efficiency folded groove waveguide （FGW） for w-band （85~110GHz） sheet beam traveling wave tube （TWT） is proposed. One stage phase velocity taper （OSPVT） was used in the FGW to enhance the electronic efficiency of a millimeter-wave sheet beam TWT. The OSPVT was realized via a change of the period of the FGW. Three FGWs with and without OSPVT were fabricated and their measured s-parameters demonstrate good transmission characteristics and wide bandwidth. Moreover， wave dispersions and phase velocities of the unchanged and OSPVT FGWs were obtained from measured transmission phases. 3-D particle-in-cell simulations of beam-wave interaction predicted that the proposed TWT with an OSPVT of twenty half periods could output a saturated power of 240 W at 95 GHz， which is about 70 W higher than the case of without OSPVT. Meanwhile， the application of the OSPVT improves the electronic efficiency in the whole operating frequency range of 85~110 GHz， with a maximum efficiency enhancement of about 47% in the vicinity of 95 GHz.

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Infrared Spectroscopy and Spectral Analysis

• Tuning the optical response of long-wavelength InAs/GaSb Type-II superlattices infrared focal plane arrays with multi-coatings

  SHI Rui, ZHOU Jian, BAI Zhi-Zhong, XU Zhi-Cheng, ZHOU Yi, LIANG Zhao-Ming, SHI Ying, XU Qing-Qing, CHEN Jian-Xin

  2022,41(1):280-284, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  Abstract:

  In this paper， the multi-coatings composed of layers of zinc sulfide and germanium were designed and fabricated on a long-wavelength InAs/GaSb Type-II superlattices infrared focal plane arrays （FPAs）. Compared with the FPAs without multi-coatings， the multi-coatings make the response peaks of the FPAs shift from the wavelength of 8.7 μm and 10.3 μm to that of 9.8 μm and 11.7 μm. The 50% response cut-off wavelength of the FPAs shifts from 11.6 μm to 12.3 μm， and the response intensity of the FPAs is increased by 69% at the wavelength of 12 μm. In summary， the multi-coatings make the response wavelength of the FPAs tunable， which provides a powerful platform for more sensitive long-wave detection and improving imaging capabilities.

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• Infrared emission efficiency of δ - doped GaSbBi single quantum well by photoluminescence spectroscopy

  MA Nan, DOU Cheng, WANG Man, ZHU Liang-Qing, CHEN Xi-Ren, LIU Feng, SHAO Jun

  2022,41(1):285-290, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (1) HTML (0) PDF (743.02 KKB)(0)

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  In this work， excitation power-dependent infrared photoluminescence （PL） measurements were carried out on four GaSb_0.93Bi_0.07/GaSb single quantum well （SQW） samples with different in-well δ-doping density as well as the corresponding reference SQW samples without doping. PL integral-intensity evolutions of the GaSbBi SQW and the GaSb barrier/substrate show a significant decrease in the infrared emission efficiency caused by the in-well δ-doping. The doping-induced relative decrease rate is about . Further analysis indicates that the reduction of the infrared emission efficiency is a co-consequence of the "electron loss" caused by the interfacial deterioration and the "photon loss" caused by the GaSbBi lattice quality deterioration. This work may be helpful in optimizing the performance of diluted Bi infrared light-emitting devices.

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Remote Sensing Technology and Application

• A neural networks based method for suspended sediment concentration retrieval from GF-5 hyperspectral images

  LIU Yi-Ming, ZHANG Lei, ZHOU Mei, LIANG Jian, WANG Yan, SUN Li, LI Qing-Li

  2022,41(1):291-304, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

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  The suspended sediment concentration （SSC） is an extremely important property for water monitoring. Since machine learning technology has been successfully applied in many domains， we combined the strengths of empirical algorithms and the artificial neural network （ANN） to further improve remote sensing retrieval results. In this study， the neural network calibrator （NNC） based on ANN was proposed to secondarily correct the empirical coarse results from empirical algorithms and generate fine results. A specialized regularization term has been employed in order to prevent overfitting problem in case of the small dataset. Based on the Gaofen-5 （GF-5） hyperspectral remote sensing data and the concurrently collected SSC field measurements in the Yangtze estuarine and coastal waters， we systematically investigated 4 empirical baseline models and evaluated the improvement of accuracy after the calibration of NNC. Two typical applications of NNC models consisting baseline model calibration and temporal calibration have been tested on each baseline models. In both applications， results showed that the calibrated D’Sa model is of highest accuracy. By employing the baseline model calibration， the root mean square error （RMSE） decreased from 0.1495 g/L to 0.1436 g/L， the mean absolute percentage error （MAPE） decreased from 0.7821 to 0.7580 and the coefficient of determination （R²） increased from 0.6805 to 0.6926. After implementation of the temporal calibration， MAPE decreased from 0.8657 to 0.7817 and R² increased from 0.6688 to 0.7155. Finally， the entire GF-5 hyperspectral images on target date were processed using the NNC calibrated model with the highest accuracy. Our work provides a universal double calibration method to minimize the inherent errors of the baseline models and a moderate improvement of accuracy can be achieved.

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• Comparative analysis of in-line and coaxial pulse tube cryocoolers at 90 K

  ZHAO Peng, JIANG Zhen-Hua, LU Zhi, QU Xiao-Ping, WU Yi-Nong

  2022,41(1):305-309, DOI:

  Abstract: (0) HTML (1) PDF (1.32 MKB)(0)

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  Linear and coaxial pulse tube cryocoolers （PTCs） are widely used in space， especially coaxial PTCs. The coaxial PTC has a compact structure and is more convenient to use， while the linear structure is simple with high cooling efficiency. At present， the research on the difference between the two PTCs based on theoretical research is relatively rare. Therefore， it is very valuable to carry out some comparative studies between the two PTCs. Two kinds of Stirling-type single-stage PTCs （in-line and coaxial type） are analyzed due to their different structures in this paper. One-dimensional numerical model is established to analyze the changes of the relevant thermodynamic parameters in the two cryocoolers. The mechanism is revealed that different structural changes could lead to different cooling performance. The differences between the PTCs are compared by analyzing the energy flows， acoustic impedance networks. Also， two experimental setups are established， and the performance of the two pulse tube cryocoolers is tested and analyzed. The results show that the in-line cryocooler has higher cooling efficiency， and the coaxial one could reach lower cooling temperature at the same input power because the pulse tube is placed in the regenerator of the coaxial system and precooled by the regenerator. By comparing the simulation data with the experimental results， it is found that there is a good consistency.

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• Analysis of radiation reference anomaly of HY-1B COCTS and research on the repair algorithm

  FAN Wen-Long, HUANG Xiao-Xian, FU Yu-Tian

  2022,41(1):310-321, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (0) HTML (0) PDF (2.62 MKB)(0)

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  The three elements of water color remote sensing products are chlorophyll， suspended substance and yellow substance. As one of the main loads of HY-1 satellite， Chinese Ocean Color and Temperature Scanner （COCTS） has set up 8 visible and near-infrared detection channels， to provide primary data for the study of global ocean primary productivity distribution. HY-1B COCTS was launched in 2007， and at the beginning of orbit entry there exists light pollution in cold space which works as the zero-radiation datum， which leads to the signal cut-off in the deep-sea area of the near-infrared detection channel， and the lower the latitude， the bigger the cold air signal is. In order to study the mechanism of the problem and repair the historical data of HY-1B COCTS， the characteristics of the source of the problem was verified in the laboratory， and the influence mechanism was analyzed. Based on the relationship between the sun glint energy of HY-1C COCTS and the solar zenith angle， the sun glint energy of HY-1B COCTS at different solar zenith angle is calculated. According to the radiometric calibration coefficient， the corresponding code value of the sun glint energy and the correction quantity can be obtained. The results show that the correction quantity is linear with the energy calculated from the solar zenith angle， and can be used to repair other target signals of HY-1B COCTS. This algorithm can be used to repair the remote sensing data of nearly 9 years of HY-1B COCTS. It lays a theoretical foundation for data comparison between the same kind of ocean remote sensing instrument and retrieving water color products.

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Infrared Photoelectric Technology and Application

• Experimental study of PbS detector irradiated by 2.79 μm mid-infrared laser

  WANG Xi, YE Qing, DONG Xiao, LEI Wu-Hu, LYU Tong-Lin, GUO Yan-Tin, HU Yi-Hua

  2022,41(1):322-329, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (0) HTML (0) PDF (5.07 MKB)(0)

  Abstract:

  It has very important application value to investigate the damage performance of PbS detector irradiated by mid-infrared laser. In this paper， the experiment research on damage in PbS detector irradiated by 2.79 μm mid-infrared laser is carried out. Furthermore， the theoretical model of PbS detector irradiated by 2.79 μm laser is developed and a numerical simulation is performed to calculate temperature distribution in PbS detector using finite element method， and the relationship between laser parameters and damage effect is also studied. The simulation and experimental results indicate that the damage mechanism of PbS detector irradiated by 2.79 μm mid-infrared laser is mainly melting damage， and the melting damage threshold is calculated to be 13.03 J/cm2. Before the temperature reaches the melting point of PbS， the thermal decomposition reaction of PbS begins， and then separates out PbO which is the yellow precipitate. It is shown that pulse repetition frequency and the number of pulses affect damage considerably， and the accumulation of multi-shot laser induced damage in PbS detector is obvious. The theoretical analysis is in agreement with the initial damage morphology of PbS surface.

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• High precision time-to-digital conversion circuit for mercury cadmium telluride APD detector at 77K

  ZHANG Qi-Wen, CHEN Hong-Lei, DING Rui-Jun

  2022,41(1):330-337, DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (0) HTML (0) PDF (1.37 MKB)(0)

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  HgCdTe avalanche photodiode （APD） is frontier research on infrared focal plane technology， High-precision time stamp"s readout circuit is the basis of the APD focal plane at 77 K， which directly affects APD infrared focal plane performance. Time-to-digital conversion circuit （TDC） is one of the methods to achieve high-precision time stamping. Based on the analysis of MOSFET device at low temperature， we design a vernier TDC circuit， which uses a synchronous counter to quantize an integer multiple of the periods to achieve a coarse count of 6 bits； We use the high-frequency clock multiplied by the on-chip phase-locked loop to quantify the part that is less than one clock cycle to achieve a fine-count of 6 bits output. The circuit adopts standard CMOS process tape out， our circuit works at a master-frequency of 120 MHz. At 77 K， the circuit tests can distinguish the time resolution of 236.280 ps. The DNL is within -0.54~0.71 LSB， and the INL is within -1.32~1.21 LSB.

Volume 41,2022 Issue 1

红外光谱与光谱分析

• Terahertz detection of thin defects thickness based on Hilbert transform and power spectrum estimation

  WANG Jie, TAN Bing-Chong, TAO Xing-Zhu, XU Cheng-Cheng, CHANG Tian-Ying, CUI Hong-Liang, ZHANG Jin

  DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (308) HTML (0) PDF (1.17 MKB)(296)

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  A spectral analysis algorithm based on the combination of Hilbert transform （HT） and power spectrum estimation has been proposed， and the terahertz reflection time domain waveform was processed. At the same time， the algorithm was applied to terahertz time domain spectroscopy imaging， defect thickness was correlated with image gray level， and the thickness， position and shape of defects in glass fiber laminate can be detected by imaging simultaneously. The experimental results show that when the multi-signal classification （MUSIC） spectrum estimation and auto regressive （AR） spectrum estimation are combined with Hilbert transform， the reflected pulses between upper and lower surfaces of defect with thickness of 0.08 mm can be successfully distinguished， the time resolution of reflected pulses is higher than 0.5 ps， and the detection error of defect thickness is no more than 0.03 mm.

Terahertz and Millimeter Wave Technology

• Design of a quasi-optical mode converter for a 170GHz gyrotron

  XU Shou-Xi, YANG Jie, WANG Hu, GENG Zhi-Hui, ZHANG Rui

  DOI:

  Abstract: (329) HTML (0) PDF (1.19 MKB)(291)

  Abstract:

  A high efficiency Denisov-type quasi-optical mode converter for a 170 GHzmode gyrotron is presented. The mode converter comprises a dimpled-wall launcher and a mirror system. Based on the coupled mode theory， the advanced launcher having two stages of perturbations is investigated. A mirror system of the converter is optimized and designed by using the vector diffraction theory. Simulation results show that the good Gaussian mode is converted from the circular waveguide mode and the mode conversion efficiency of a quasi-optical mode converter is 93.7%.

遥感技术与应用

• The research on lightweight SAR ship detection method based on regression model and attention

  LI Li-Yuan, LI Xiao-Yan, HU Zhuo-Yue, SU Xiao-Feng, CHEN Fan-Sheng

  DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (133) HTML (0) PDF (1.33 MKB)(313)

  Abstract:

  Synthetic aperture radar (SAR) has the advantages of all-sky and all-weather earth observation without cloud interference. Ship detection based on SAR images has been widely used in civil and military fields, including maritime search and rescue, port reconnaissance, territorial sea defense. However, different from large ships, the misdetection rate of small ships with fewer pixels and lower contrast is high. And it is difficult to balance speed and accuracy during on-orbit ship detection. To solve the above problems, an improved lightweight ships detection method (ImShips) based on YOLOv5s is proposed. Firstly, the standard convolution with small receptive field is adopted at the bottom of the baseline to obtain spatial information of small ships. And the dilated convolution with enlarged receptive field is added at the top of the baseline to preserve more semantic features, which is conducive to extract large targets feature. Then, a lightweight channel attention mechanism is applied to the backbone and neck of YOLOv5. And the weight is allocated to filter more important texture information. Finally, the depth-wise separable convolution is adopted to replace the standard convolution during down-sampling to reduce the number of parameters and improve the inference speed. Compared with YOLOv5s model, the experimental results show that ImShips achieves an increase in AP, while the FLOPs are reduced by 45.61%, and the speed is increased by 8.31% in SSDD and ISSID datasets. The speed and accuracy of ImShips model are improved effectively for sea surface object detection. The proposed method has great application potential in on-orbit ship detection.

红外光谱与光谱分析

• Near-field imaging of WTe₂

  DAI Zhen-Bing, LUO Guo-Yu, HE Yan, WANG Chong, YAN Hu-Gen, LI Zhi-Qiang

  DOI: 10.11972/j.issn.1001-9014.2021.06.014

  Abstract: (320) HTML (0) PDF (1.30 MKB)(342)

  Abstract:

  Near-field optical response of WTe₂ thin films was studied by use scanning near-field optical microscopy （SNOM） ， we have observed bright fringes near the edge of the thin film sample and also a thickness dependence on optical contrast to the sample and substrate. To understand this behavior， first we obtain the dielectric function of WTe₂ at room temperature by Drude-Lorentz model via fitting the infrared radiation （IR） reflectance and conductivity spectra， then the near-field ratio of thin film sample to the diamond substrate is calculated by the Finite-dipole model. The experimental result reveals that the behavior of the sample cannot be fully described by the bulk properties. We assume that a decoupled thin layer exists on the surface of the bulk. There are two possible explanations for the observation of the near-field patterns of bright outside fringes. Firstly， a hot-spot field may be produced between the tip and the sample edge due to the enhancement of the local electric field under the IR illumination， a similar behavior has been revealed in surface-metallic black phosphorus. Another probability is that the topological edge states of top decoupled monolayer WTe₂ lead to an enhancement of the local optical conductivity. This work provides a reference from the optical research of topological materials in the future.

Infrared Materials and Devices

• Studies on the surface treatment of InAs/GaSb type-II super-lattice long-wave infrared detectors

  CUI yu-rong

  DOI: 10.11972/j.issn.1001-9014.XXXX.XX.001

  Abstract: (569) HTML (0) PDF (0.00 ByteKB)(237)

  Abstract:

  In this work， the surface treatment of InAs/GaSb type-II super-lattice long-wavelength infrared detectors is studied. An optimizing process of N₂O plasma treatment and rapid thermal annealing was developed， which can improve the performance of long-wavelength detector with λ_{50% cut-off}=12.3μm from 5.88 ×10^-1A/cm² to 4.09 ×10^-2A/cm² at liquid nitrogen temperature， -0.05V bias. Through variable area device array characterization， the sidewall leakage current was extracted. Under zero bias， the surface resistivity improved from 17.9Ωcm to 297.6 Ωcm. However， the sidewall leakage couldn’t be ignored under large inverse bias after optimizing process， where surface charge might induce the surface tunneling current. It is verified by gate-control structure that there are two main leakage mechanisms in long-wave device： pure sidewall parallel resistance and surface tunneling. At last， the surface charge was calculated to be 3.72×10¹¹cm^-2 by IV curve fitting after optimizing process.

• Study on surface current properties of ZrTe5 excited by ultrafast laser

  LV Hai-Hui, LI Min, XIA Yu, LIU Zheng, HE Ming-Yang, YUAN Shuai, ZENG He-Ping

  Abstract: (4) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  We measured the transient photocurrent generated by femtosecond light excitation on the surface of Dirac semimetal ZrTe5 through the reflected terahertz time-domain spectroscopy. Our experimental results reveal several physical mechanisms of terahertz radiation generated from ZrTe5. The results show that the polarization-independent photocurrent is the main component of the surface current, and the terahertz amplitude is related to polarization of the pump pulse, which indicates that part of the current is caused by nonlinear optical rectification effect. Under circularly polarized light pumping, the terahertz amplitude changes four times periodically with the pump pulse, which confirms that circular photogalvanic effect of ZrTe5. Besides, we have analyzed the terahertz time-domain electric field excited by ultrashort laser pulses. The ZrTe5 inversion symmetry is broken under the excitation of the femtosecond pulse, which produces B1u phonons, forming a transient Weyl point, and undergoing a phase transition from the Dirac state to the Weyl state. This is of great significance to the study of topological phase transitions and other topological states.

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• Influence of InyAl1-yAs graded buffer layer on properties of InP-HEMT materials

  TIAN Fang-Kun, AI Li-Kun, SUN Guo-Yu, XU An-Huai, HUANG Hua, QI Ming

  Abstract: (6) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  This paper reports the material characteristics of In0.66Ga0.34As/InyAl1-yAs high electron mobility transistor (HEMT). The linearly graded InyAl1-yAs buffer layer was grown on InP substrates by gas source molecular beam epitaxy (GSMBE). The influence of InyAl1-yAs graded buffer layer with different thickness and different indium contents on the surface quality, the electron mobility and the concentrations of two-dimensional electron gas (2DEG) were studied. It was found that the electron mobility and concentration at 300 K (77 K) were 8570 cm2/(Vs)-1 (23200 cm2/(Vs)-1) and 3.255×1012 cm-2 (2.732×1012 cm-2). The surface morphology of the material was also well improved and the root mean square (RMS) was 0.154 nm when the InAlAs graded buffer layer thickness was 50 nm. And this study can provide strong support for the improvement of HEMT performance.

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• High efficiency 285GHz tripler based on face-to-face differential configuration

  TIAN Yao-ling, LIU Ge, LI Li, HE Yue, HUANG Kun, JIANG Jun, ZHANG Jian

  Abstract: (13) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  A high efficiency 285GHz Schottky diode tripler has been demonstrated based on the face-to-face differential configuration. The proposed concept could improve the power handling capability by a factor of two compared to the traditional balanced circuit with on-chip capacitors. Meanwhile, the tripler could provide improved DC bias networks with perfect amplitude and phase balance, which shows lower insert losses by leaving out the high required on-chip bypass capacitor. The proposed triple frequency multiplier features inherent suppression on even-order harmonics with the face-to-face differential topology, which ensures better conversion efficiency with doubled anodes. The fabricated tripler has been proved to exhibit a 12% peak efficiency for a nominal driven power of 140~210mW.

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• Research on high temperature performance of long-wave p-on-n HgCdTe infrared focal plane detector

  XIONG Bo-Jun, ZOU Lei, YANG Chao-Wei, QIN Qiang, KONG Jin-Cheng, LI Li-Hua

  Abstract: (22) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The material of the HgCdTe infrared detector is a narrow band gap semiconductor.As the operating temperature increases,the intrinsic carrier concentration of the material will increase,the detector cut-off wavelength will become shorter, and the dark current will increase,which will cause the performance of the device to decrease.HgCdTe infrared detectors usually work near 77K temperature and obtain good detection performance, but low temperature operation will increase the preparation cost,power consumption,volume and weight of the detector.In order to solve these problems, under the premise of ensuring the normal working performance of the detector, increasing the operating temperature of the detector is an important research direction of the HgCdTe infrared detector.The p-on-n structure HgCdTe infrared focal plane detector has the characteristics of low dark current and long minority carrier life,which is conducive to obtaining better high-temperature performance devices.The performance of the p-on-n long-wave focal plane detector is tested and analyzed at different operating temperatures. At 110 K, the NETD of the p-on-n long-wave HgCdTe infrared focal plane detector is 25.3 mK,and the operability is 99.48%,Have better working performance under high temperature conditions.

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• Detection of oxygen residual concentration in glass medicine bottles based on peak width correction

  SHEN Shuai, HE Jian-Jun

  Abstract: (31) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The oxygen residue in the glass medicine bottle poses a serious threat to the sterility of the medicine in the bottle. In this paper, the peak height of the second harmonic signal demodulated by wavelength modulated spectrum (WMS) technology is used as the basis of oxygen concentration inversion. However, when measuring gas concentration with second harmonic signal, the change of modulation depth will lead to the change of second harmonic peak, which will usually bring errors to the system and reduce the inversion accuracy of concentration. However, the modulation depth is affected by the fluctuation of modulation current, temperature and pressure, and cannot be calculated directly. To solve this problem, we first successfully convert the relationship between modulation depth and secondary harmonic peak height into the relationship between secondary harmonic peak width and peak height. Then, the gas concentration is inversed by using the harmonic peak height after being corrected by peak width. Preliminary experiments show that when using the harmonic peak height after peak width correction to predict the gas concentration in the bottle, not only the accuracy of the system is improved by 2.1%, but also the overall robustness of the system is improved.

  • 1
• A forward calculation method to quickly realize the achromatic metasurface for arbitrary polarization control

  Yu Fei-Long, Chen Jin, Zhao Zeng-Yue, Li Guan-Hai, Chen Xiao-Shuang, Lu Wei

  Abstract: (19) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In recent years, many advances have been made in polarization control and dispersion control of artificial microstructure. However, it is still a challenge to realize achromatic control of arbitrary polarization because the traditional way to calculate the manipulation of metasurface on elliptic polarization have to solve the equation for each piece of data. A direct calculation method based on coordinate transformation is proposed to quickly calculate the manipulation of metasurface elements on arbitrary polarization states. An achromatic focusing metasurface lens based on all-Si elliptic cylinder structure is designed to manipulates elliptical polarization states in the mid-infrared band. The result shows that this method and design can effectively control the elliptic polarization state under the condition of greatly simplifying the calculation process. Compared with the previously reported design based on circular polarization or non-polarization dependence, the application scope of the dispersion control of the metasurface is further expanded.

  • 1
• Terahertz photodetector based on two-dimensional tellurene

  HUANG Wen-Chao, ZHANG Kai-Xuan, LI Yun-Xia, WANG Lin

  Abstract: (40) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The abundant physical, chemical and biological information of terahertz wave makes the optical detection technology of this wave band have important application potential in civil and military fields. Two-dimensional (2D) materials, such as graphene, black phosphorus, etc., have been proven to be candidates for high-performance infrared-terahertz photodetectors and have been extensively studied. However, problems such as the dark current of graphene and the instability of black phosphorus in the air hinder the rapid development of terahertz detection at room temperature. In this work, a metal-tellurene-metal terahertz photodetector, and realized optical detection under millimeter wave-terahertz wave are fabricated. The results show that the terahertz photodetector based on logarithmic antenna tellurene has a high optical responsivity (40mA/W, 0.12THz) under zero bias, a response time of 8μs, and a noise equivalent power (NEP) of 4 pW?Hz^(0.5). This research results provide a new development path for high-performance room temperature terahertz optical detection.

  • 1
• Multiblock compressed sensing imaging in real time

  LIHU, Liu Xue Feng, Yao Xu Ri, Liu Fan, DouShenCheng, Hu Tai, Zhai Guangjie

  Abstract: (30) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Imaging sensors in medium and long-wave infrared spectrum are extremely expensive. Therefore, for most consumers, remote high-resolution imaging and real-time display in these spectrums are still a challenge. This paper proposes an effective block compressed sensing method called Multi-block Combined Compressed Sensing (MBCS) adapting to Focal Plane Array Compressed Imaging system (FPA CI), which combines parallel sampling and fast reconstruction. High-resolution images can be reconstructed from low-resolution measurement results in real-time using a low-resolution infrared sensor. The results showed that, compared with the traditional CS-based super-resolution method, this method can greatly improve the quality of the reconstructed high-resolution image and achieve a higher reconstruction speed. The optical prototype architecture and construction of the MBCS measurement matrix for the reconstruction model are also discussed. This study evaluated the reconstruction performance in terms of the block size and found that the optimal block size needs to consider both speed and reconstruction quality. Furthermore, the MBCS reconstruction algorithm with GPU acceleration was implemented to improve the image reconstruction speed of the highly parallel image system. In the experiment, the optical system and the strategy of rapid imaging and reconstruction were verified via simulation and optical experiments, which showed that the imaging speed of 512×512 resolution can reach 5 Hz.

  • 1
• Lateral Linear Mode Avalanche Photodiode Through 0.35 μm High Voltage CMOS Process

  JU Guo-Hao, CHENG Zheng-Xi, CHEN Yong-Ping

  Abstract: (20) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  This letter reports on a lateral linear mode avalanche photodiode through 0.35 μm high voltage CMOS process. The linear mode avalanche photodiode is designed and fabricated with the lateral separate absorption, charge and multiplication (SACM) structure using an epitaxial wafer. The DNTUB layer, DPTUB layer, Pi layer and SPTUB layer are used for the lateral SACM structure. This improves freedom of the design and fabrication for monolithic integrated avalanche photodiode with no high voltage CMOS process modifications. The breakdown voltages for the lateral linear mode avalanche photodiode is about 114.7 V. The dark currents at gain M = 10 and M = 50 are about 15 nA and 66 nA, respectively. The effective responsive wavelength range is 450 - 1050 nm. And the peak responsive wavelength is about 775 nm at 20 V while M = 1. With unity gain (M = 1), the responsivity at 532 nm is about half of the maximum.

  • 1
• Tunable dual-wavelength semiconductor laser based on indium-rich cluster quantum structure

  LI Xue, TAI Han-Xu, WANG Yu-Long, ZHENG Ming, Jianwei Zhang, Zhang Xing, NING Yong-Qiang, Wu Jian, WANG Li-Jun

  Abstract: (34) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  We design and fabricate a double-wavelength tunable laser with a single grating structure using a single-gain chip. The gain chip adopts an indium-rich cluster quantum constraint structure, which can generate ultra-wide flat-top gain. Flat-top gain is the basis for producing a dual-wavelength laser with the same intensity. A grating is inserted into the exterior of the gain chip so that its resonator is composed of internal and external cavities. The internal cavity consists of two natural cleavage planes of the gain chip for oscillating the output laser at a fixed wavelength (974 nm). The tunable external cavity consists of a natural cleavage plane and a grating for the output laser at a tunable wavelength (969.1–977.9 nm). The laser structure of the single-gain chip and single grating can produce synchronous dual-wavelength output, which avoids a complicated optical path design. The frequency difference of the two wavelengths is in the terahertz band. Thus, the laser can be used as a dual-wavelength laser source to generate terahertz radiation.

  • 1
• Research on millimeter-wave ridged half-mode waveguide filter based on periodic defected ground structure

  Zhou Qi-Hui, LIU Chen-Xi

  Abstract: (38) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  A monolithic ridged half-mode waveguide bandpass filter with a periodic defected ground array has been successfully fabricated. Utilizing the high-pass characteristic of the waveguide and the rejection band generated by the periodic defected ground structure, an effective passband was created. The measured results show a 3 dB passband from 39.4 to 45.4 GHz, centered at 42.4 GHz with a 3-dB fractional bandwidth of 14.1%. The lowest insertion loss of 2.4 dB locates at 44.2 GHz. The suppression in upper rejection band reaches 40 dB at 58 GHz. Compared to conventional rectangular waveguide filters, the width of the proposed filter is reduced by 64%, which benefits to the integration and miniaturization. With the development of the next generation wireless communication (5G) towards millimeter-wave band, the miniaturized millimeter-wave filter has promising potential for 5G communication.

  • 1
• Highly Sensitive Graphene Terahertz Detection Driven by two-dimensional Ferroelectrics

  WANG Xue-Yan, Zhang Yi-Wen, Wang Lin, Chen Xiao-Shuang

  Abstract: (50) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Graphene has the excellent characteristics of low defect density, easy large-area transfer and high carrier mobility. However, the zero-bandgap band structure of graphene leads to a short lifetime of photogenerated carriers, which restricts its application in highly sensitive photodetectors. In this work, ferroelectric material CuInP2S6(CIPS) was used as the top gate to control the photoelectric characteristics of graphene, and the possibility of improving the sensitivity of graphene terahertz detector was explored. The detection mechanism of graphene photothermoelectric effect and plasma wave effect under ferroelectric control was studied, and a high-performance graphene detector was obtained. At 0.12 THz, the responsivity of detector at room temperature reaches 0.5 A/W, with the response time of 6.3 μs and the noise equivalent power(NEP) of 0.81 nW/Hz1/2 under a bias voltage of 40 mV and a gate voltage of 2.12 V. At 0.29 THz, the responsivity is determined to be 0.12 A/W, and a NEP is 1.78 nW/Hz1/2. This work demonstrates the great potential of two-dimensional ferroelectric heterostuctures at THz band.

  • 1
• Relationship between radar reflectivity factor and ice water content of non-spherical cirrus ice crystals at 220 GHz

  WANG Biao, HUO Yi-Wei, GUO Xing, WU Jia-Ji

  Abstract: (22) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  For the practical needs in the data processing of terahertz radar，the discrete dipole approximation method is used to calculate the backscattering cross-section of non-spherical ice crystals with different shapes. Based on the latest refined ice cloud model, the relationship between the radar reflectivity factor Zm and ice water content I in 220 GHz is established. The calculation results show that both the shape of the non-spherical ice crystals and the ice cloud model have a particular influence on the Zm-I relationship. This study has application value for cloud parameter inversion of mid-latitude cirrus clouds, and it can be helpful for the development of terahertz radar in the detection of clouds.

  • 1
• Infrared image dehazing based on hierarchical subdivision superpixels and information integrity prior

  LI Wei-Hua, LI Fan-Ming, MIAO Zhuang, TAN Chang, MU Jing

  Abstract: (78) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Hazy weather degrades the contrast and visual quality of infrared imaging systems due to the presence of suspended particles. Most existing dehazing methods focus on enhancing global image contrast or exploit a local grid window strategy, which may lead to loss of information, halo artifacts and distortion in sky region. To address these problems, this paper proposes a novel single image dehazing model based on superpixel structure decomposition and protection of information integrity. In this model, based on the local structure information, the image is first adaptively divided into multiple objective regions using a superpixel segmentation algorithm to eliminate halo artifacts. Meanwhile, to avoid the error estimate caused by the local highlighted targets, a modified quadtree subdivision based on superpixel blocks is applied to obtain the global atmospheric light. Furthermore, a combined constraint is used to optimize the transmission map by minimizing the loss of information. Compared with state-of-the-art methods in terms of qualitative and quantitative analysis, experiments on real-world IR image data demonstrate the efficacy of the proposed method in both contrast and visibility.

  • 1
• A Wideband Injection-Locked Frequency Tripler

  WAN Cao, XUE Quan

  Abstract: (65) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  A wideband injection-locked frequency tripler (ILFT) is proposed. Based on the conventional injection method, the tripler used a push-push differential pair to double the frequency of the input signal and coupled the generated second harmonic to the source common mode node of the injectors through a transformer, which enhanced the second harmonic at the source common mode node of the injectors. Since the injection current is generated by mixing the injected signal with the second harmonic at the source common mode node, the injection current is also enhanced, thereby increasing the locking range. In addition, the tripler adopted a fourth-order resonator, as a result, the phase of the resonant impedance is flattened at the zero-crossing point, then the locking range is further increased. The tripler is implemented in a standard CMOS 65nm process with a chip area of 720×670 um2, and the power consumption is 15.2 mW under a 1.2-V power supply. With 0 dBm power injection, the locking range is 19.2-27.6 GHz, and the corresponding fundamental suppression ratio is greater than 25 dB, and the second harmonic counterpart is beyond 35 dB. The proposed ILFT is capable of the requirements of the oscillation source in the 5G transceiver.

  • 1
• Distortions of terahertz pulses induced by the air coherent detection technique

  Du Hai-Wei, Long Jiang

  Abstract: (76) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Terahertz air coherent detection technique is a broadband detection method, which has been widely used in the broadband terahertz technology after its demonstration in the experiment. The frequency response of this method is determined by the duration of the probe laser pulse. Thus, the different probe lasers might induce distortions of terahertz pulses during the detection process. In this paper, the distortions and the energy loss of the terahertz pulses induced by the air coherent detection technique are quantitatively investigated based on the simulations. The results show that the pulse distortions and the energy loss depend on the duration of the probe laser pulse and the central frequency of terahertz pulse to be detected. This work will help to estimate the influence of the air coherent detection technique in the broadband terahertz technology.

  • 1
• Anisotropic tunable multi-order strong coupling in black phosphorous nanodisk-sheet plasmonic system

  HAN Li, XING Huai-Zhong

  Abstract: (85) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Black phosphorus supports anisotropic surface plasmons, which can be used to design principle devices with more functions. The hybridization behavior of different plasmon modes in the sheet-disk-sheet system based on black phosphorus in the mid-infrared to far-infrared waveband is numerically simulated by the finite-difference time-domain method. By dynamically adjusting the carrier concentration in the black phosphorus, the generation and control of the strong coupling phenomenon in the two lattice directions can be realized. Analyzing and calculating the coupling between different modes, the Rabi splitting energy in the absorption spectrum can be as high as 42.9 meV. In addition, the influence of the polarization angle on the strong anisotropic coupling is also calculated, which can achieve up to 6 absorption bands. The proposed model provides a basis for the construction of compact anisotropic plasmonic devices based on two-dimensional materials that will work in the mid-to-far infrared bands in the future.

  • 1
• Nonlinearity correction of FY-3E HIRAS-II in pre-launch thermal vacuum calibration tests

  YANG Tian-Hang, GU Ming-Jian, SHAO Chun-Yuan, WU Chun-Qiang, QI Cheng-Li, HU Xiu-Qing

  Abstract: (93) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The High-spectral Infrared Atmospheric Sounder II (HIRAS-II) is a Fourier transform spectrometer onboard the world’s first civil early-morning-orbiting FengYun 3E (FY-3E) meteorological satellite, the FY-3E/HIRAS-II focus on a number of upgrades such as the sensitivity of the detector, the accuracy of spectral calibration and radiometric calibration, with the designed and manufactured processing based on the first Chinese hyperspectral infrared (IR) sounder FY-3D/HIRAS-I. We conducted a comprehensive pre-launch thermal vacuum (TVAC) calibration tests for HIRAS-II, including the nonlinearity (NL) correction which consist an essential part of radiometric calibration, the NL correction has considerable effects on radiometric accuracy. According to the HIRAS-II nonlinear behavior of the detectors for long-wave (LW) and mid-wave (MW) infrared spectral bands, the NL correction of raw data in the spectral domain is a scaling of the observed spectrum, the NL correction coefficients are derived by the methods of minimizing the spread of the responsivity functions with varying temperature, or minimizing the spread of the bias of brightness temperature among calibration targets with varying temperature. The bias of spectral brightness temperature is assessed by comparing the NL correction and the non-NL correction radiometric calibration data, the results show that, the radiometric accuracy has been significantly improved via NL correction.

  • 1
• High birefringence hollow-core anti-resonant terahertz photonic crystal fiber with ultra-low loss

  HUI Zhan-Qang

  Abstract: (78) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  An ultra-low loss and high birefringence hollow core anti-resonant terahertz photonic crystal fiber based on cyclic olefin copolymer (COC) is proposed. The cladding of the fiber consists of two groups (six in total) nodeless embedded sleeves. The guided wave characteristics are analyzed by using the finite difference time domain method combined with the perfectly matched layer boundary conditions. The simulation results show that the total transmission loss is less than 0.1 dB/m, birefringence is more than 2.12 × 10-5 within the range of 0.8 THz - 1.35 THz, dispersion in ± 0.027 ps/THz/cm. At 1.12 THz, the minimum total transmission loss is only 0.543 × 10-2 dB/m, birefringence value 2.06 × 10-4. The bending performance of the fiber is analyzed. It is shown that in y direction, when the bending radius is more than 19 cm, the bending loss is less than 0.1 dB/m, and the bending performance is good.

  • 1
• Retrieval of supercooled water in convective clouds over Nagqu of the Tibetan Plateau using Millimeter-wave radar measurements

  Ren Tao, ZHENG Jia-Feng, LIU Li-Ping, ZOU Ming-Long, CHEN Shao-Jie, HE Jing-Shu, LI Jian-Jie

  Abstract: (134) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Abstract: Supercooled water in convective clouds has always been a difficult point in meteorological detection. In this paper, based on Doppler spectra of a Ka-band millimeter-wave radar used in the third Tibetan Plateau Atmospheric Experiment and relevant radiosonde data, an algorithm for identifying and retrieving supercooled water in convective clouds over Nagqu of the Tibetan Plateau was proposed. Subsequently, retrieval effects of the algorithm were analyzed using two convective cases (including stratocumulus, cumulus humilis, and altocumulus clouds), and verified by comparing with measurements from a co-located microwave radiometer (MWR). Finally, two useful empirical relations of effective radius–radar reflectivity (R_e–Z_e) and liquid water content–radar reflectivity (LWC–Z_e) for the supercooled water in convective clouds over Nagqu were presented. The main findings are as follows: The stratocumulus, cumulus congestus, and altocumulus clouds over Nagqu are dominated by updrafts with rapid changes on the hydrometeor phase in the vertical orientation, resulting widely distributions of the formed supercooled particles in terms of both their Z_e, R_e, and LWC. Supercooled particles in different convective cloud types also locate at different cloud body positions. The velocity of the in-cloud updraft is highly and positively correlated with the supercooled water Z_e, R_e, and LWC. They possess similar temporal variations and coincident spatial distributions. The retrieved spatial positions and microphysical parameters of the cloud supercooled water are consistent with the conclusions of previous studies and observations. The radar-derived LWP are also proved to agree well with the counterparts of MWR with similar temporal variations and value peaks. Their correlation coefficients can approach 0.63–0.79. For convective clouds of the Tibetan Plateau, R_e and Z_e of the supercooled water exhibit a confident power empirical relations, namely, R_e=195.4Z_e^1.78+8 for cloud droplets and R_e=67.8Z_e^0.3 for raindrops, respectively. Supercooled raindrops also possess a certain LWC–Z_e, that is LWC=0.024Z_e^0.82, whereas, the power-form relation for the cloud droplets is inapparent.

  • 1
• Study on the improvement of scan mirror thermal radiation correction on the calibration accuracy of FY-4A AGRI

  LI Xiu-Ju, WANG Bao-Yong, WU Ya-Peng, HAN Chang-Pei, CAO Qi, ZHOU Shu-Tian, WANG Wei-Cheng, LI Pan-Pan

  Abstract: (157) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The Advanced Geostationary Radiation Imager (AGRI) is one of the main payloads of Fengyun-4A (FY-4A). In order to satisfy requirements of high-precision quantitative application of AGRI long-wave infrared (LWIR) remote sensing data, the function model of scan mirror thermal radiation changing with mechanical rotation angle is constructed, and a correction algorithm for remote sensing data of on-board blackbody and earth scene observation is presented. Based on the on orbit data of FY-4A AGRI, the dependence of the model parameters on the scan mirror temperature is analyzed, and the improvement effect of the correction algorithm on the calibration accuracy of LWIR is studied and evaluated. In the stationary period of scan mirror temperature field, the calibration deviation of B11(8.0~9.0μm), B12(10.3~11.3μm), B13(11.5~12.5μm) can be improved significantly by -2.81K~+1.06K, -0.60K~+0.19K, -0.68K~+0.24K respectively. The result of cross calibration validation with IASI show that the improved on orbit calibration brightness temperature bias is better than 0.5K@290K.

  • 1
• Research on p-on-n LWIR and VLWIR HgCdTe infrared focal plane detectors technology

  LI Li-Hua, XIONG Bo-Jun, YANG Chao-Wei, LI Xiong-Jun, WAN Zhi-Yuan, ZHAO Peng, LIU Xiang-Yun

  Abstract: (119) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The p-on-n structure doped with As implantation has the advantages of low dark current,high R0A product, and long minority carrier lifetime,which is an important trend in the development of long-wavelength and very long-wavelength HgCdTe infrared focal plane detectors. P-on-n LWIR and VLWIR HgCdTe infrared focal plane detectors with cut-off wavelength of 9.5μm and 10.1μm at 77 K and 14.97 μm at 71 K fabricated by Kunming Institute of Physics are introduced.Test and analyze performance parameters such as the responsivity, NETD, dark current and R0A of the detectors. The test results show that the operable pixel factor of the detectors is between 99.78% and 99.9%,and the NETD of the detectors is less than 21 mK. The effective fabrication of p-on-n LWIR and VLWIR HgCdTe infrared focal plane detectors is realized.

  • 1
• Analysis and verification of the positioning accuracy of a flat-panel detector used for precision pointing in space optical communication

  WANG Xu, Tu Cheng-Xiang, ZHANG Liang, WANG Jian-Yu

  Abstract: (172) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  To realize a high-precision link in space optical communication, we analyzed key factors that affect the accuracy of flat-panel detectors in terms of target positioning. The error of the centroid algorithm was analyzed from the mechanism and the necessity of satisfying the spatial lossless sampling condition was verified by using a simulation. The defined NU value served as an indicator in quantifying the nonuniformity of the detector. As the NU value increased linearly, the positioning error of the centroid continued to increase, whereas the speed reduced. When the NU value was 0.005, the maximum positioning error was 0.043 pixels. Considering that the light intensity of the target incident on the optical system varies constantly, the smaller the NU value, the closer the centroid is to the true position of the light spot. Furthermore, the pixel response of a typical complementary metal oxide semiconductor (CMOS) detector was experimentally tested under different illumination intensities. Based on the response curve, a mathematical model for the nonuniformity of the pixel response was established. It can be determined that the NU value fluctuates from 0.0045 to 0.0048 within the linear response range. The experimental results of the spot centroid positioning accuracy verify that the absolute positioning error is less than 0.05 pixels, which satisfies the requirements of high-precision links. Therefore, the effectiveness of the theory and simulation presented in this study can be validated.

  • 1
• Design of a novel Y-junction electro-optic modulator based on thin film lithium niobite

  GuoHongjie, LIU Hai-Feng, WANG Zhen-Nuo, TAN Man-Qing, Lei Ming, LI Zhi-yong, GUO Wen-Tao, GUO Xiao-Feng

  Abstract: (173) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In recent years, the high-performance electro-optic modulator based on Thin-film lithium niobate (TFLN) platform has been receiving considerable attention due to the featuring small-footprint and low energy loss. In this paper, a novel Y-junction electro-optic modulator with a vertical electrode structure was designed based on TFLN. The relationship between the low half-wave voltage and the buffer layer thickness for the novel modulator was investigated. Meanwhile, the design parameters of Y-junction were optimized, and found that the half-wave voltage is less than 1.5 V and the insertion loss is less than 5 dB. Finally, the Y-junction electro-optic modulator was fabricated. This study not only provides insights on the design and realization of compact footprint photonic waveguides in TFLN platform, but also, experimental evidences for fabrication of electro-optic modulator with high-performance and multifunction.

  • 1
• Recent Progress on Natural Biomaterials Boosting High-Performance Perovskite Solar Cells

  Shaobing Xiong, Qinye Bao, Junhao Chu

  Abstract: (159) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Perovskite solar cells (PeSCs) have been considered as one of the most promising photovoltaic technologies due to their high efficiency, low-cost and facile fabrication process. The power conversion efficiency and stability of PeSCs highly depend on the quality of perovskite film and the interfaces in the device, which are the main sources of PeSC nonradiative recombination losses. Natural biomaterials, with the advantages of earth-abundance, non-toxicity, and biocompatibility, have shown huge potential to improve both perovskite layer and interfaces in PeSCs. Herein, the latest progress using natural biomaterials to achieve high-performance PeSCs is reviewed. We firstly discuss the roles of natural biomaterials on perovskite film in terms of morphology optimization, defect passivation and energetics modification. Meanwhile, the strategies using natural biomaterials to create superior interface between perovskite and charge transport layer, and to build stretchable, biocompatible, and biodegradable electrodes are present. Finally, an outlook on the further development of PeSCs with respect to natural biomaterials is provided.

  • 1
• Fast moving target detection algorithm based on LBP texture feature in complex background

  QIU Li-Ya, CHEN Wei-Lin, LI Fan-Ming, LIU Shi-Jian, LI Zheng, TAN Chang

  Abstract: (203) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In the visible and infrared scenes with complex background, such as rain and snow weather, leaf swaying, shimmering water, etc., fast and accurate extraction of a complete target has always been the primary problem in moving target detection. In order to be real time and aiming at the problems of existing video foreground extraction algorithms, such as dependence on prior information, low recall rate, lack of texture and large noise, a background modeling method based on histogram statistics and improved LBP（Local Binary Pattern） texture features is proposed. Firstly, the mode of each pixel histogram is used as the reference background without prior knowledge, which saves a lot of storage space. Then, an improved S_MBLBP texture histogram is proposed to model the background with the reference background by using neighborhood compensation strategy, which eliminates most of the dynamic background and illumination changes, and realizes the accurate extraction of the target. Experimental results show that the proposed algorithm can quickly extract foreground targets in a variety of complex infrared and visible scenes, and can improve the accuracy and recall rate at the same time.

  • 1
• A THz-TDS based Metamaterial Sensor for Sensitive Distinguishment of Food Additives

  MA Jia-Lu, TANG Jing-Chao, WANG Kai-Cheng, GUO Liang-Hao, WANG Shao-Meng, GONG Yu-Bin

  Abstract: (330) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  A sensitive terahertz (THz) metamaterial sensor for the distinguishment of common additives in the food industry is proposed. The metamaterial sensor consists of an array of split ring resonator (SRR) with double tip ends. By checking the resonate frequency shift of the sensor, the concentration and the type of the solution sample can be distinguished. The metamaterial sensor is fabricated on a quartz substrate, which is transparent for THz wave. The solutions with the concentration of 0.2, 0.4, 2 and 4mg/ml have been measured by using a terahertz time domain spectroscopy (THz-TDS). The results illustrate that the proposed metamaterial sensor can detect the concentration of the solution sample, as low as 0.2mg/ml. Meanwhile, different solutions with same concentration can also be clearly distinguished. Our study provides new insights for the application of terahertz metamaterial sensor based on SRR structure in the field of food safety.

  • 1

Volume 41,2022 Issue 1

• LOW-TEMPERATURE RAMAN SCATTERING SPECTRA AND ELECTRICAL PROPERTIES OF Cd_1-xZn_xTe(x=0.04) OF DIFFERENT SURFACE TREATMENTS

  PEI Hui-Yuan

  2001,20(3):184-188, DOI:

  Abstract: (1310) HTML (139) PDF (262.82 KKB)(37704)

  Abstract:

  测量了几种不同处理的Cd1-xZnxTe(x=0.04)表面的傅里叶变换拉曼散射光谱和电流－电压（I－V）特性。通过分析拉曼光谱反Stokes分量，并与表面I－V特性进行比较，结果表明与表面处理相联系的晶格声子的行为反映了表面完整性的变化，Te沉淀是影响表面质量的关键因素，并对有关表面处理方法的实际应用进行了讨论。

• OPTICAL PROPERTIES OF PbTiO3 THIN FILMS PREPARED BY A MODIFIED SOL-GEL PROCESSING

  HU Zhi Gao WANG Gen Shui HUANG Zhi Ming CHU Jun Hao

  2002,21(3):175-179, DOI:

  Abstract: (7450) HTML (465) PDF (411.06 KKB)(19220)

  Abstract:

  采用溶胶－凝胶法在石英玻璃衬底上制备出均匀透明的无定形PbTiO3薄膜，并对其 光学性质进行了详细的研究，发现其折射率的波形符合经典的Cauchy函数。由半导体理论计算得到无定形的PbTiO3薄膜的光学禁带宽度为3．84eV.FTIR透射光 谱研究表明无定形PbTiO3薄膜在中红外波段没有吸收峰出现，对于在550℃下 快速热退火得到的PbTiO3薄膜，通过远红外反射光谱测量，观察到了6个约外活性声子膜。

Infrared Spectroscopy and Spectral Analysis

• DETECTING THE MELAMINE OF PURE MILK BY NEAR INFRARED SPECTRA

  XU Yun, WANG Yi-Ming, WU Jing-Zhu, ZHANG Xiao-Chao

  2010,29(1):53-56, DOI:

  Abstract: (10209) HTML (415) PDF (221.64 KKB)(12610)

  Abstract:

  NIRS was used in rapid qualitative and quantitative detection for melamine of pure milk in this paper. Experiment was conducted by preparing two groups pure milk samples which melamine content is different for qualitative analysis and quantitative analysis. By combining NIRS technology with the cluster analysis method, A effective classification can be made on the two kinds of milk samples with and without melamine; To achieve this, spectrum pretreatment and wave length choice methods were employed before model optimization. The results showed that NIR models of predicting melamine content in pure milk has good stability and predictive ability.This paper suggested that NIR could be used as a quick, green and convenient method for predicting melamine content of dairy.

• INFRARED OBJECT TRACKING BASED ON PARTICLE FILTERS

  CHENG Jian, ZHOU Yue, CAI Nian, YANG Jie

  2006,25(2):113-117, DOI:

  Abstract: (7067) HTML (402) PDF (271.63 KKB)(12265)

  Abstract:

  The particle filter is an effective technique for the state estimation in non-linear and non-Gaussian dynamic systems. A novel method for infrared object robust tracking based on particle filters was proposed. Under the theory framework of particle filters, the posterior distribution of the infrared object is approximated by a set of weighted samples, while infrared object tracking is implemented by the Bayesian propagation of the sample set. The state transition model is chosen as the simple second-order auto-regressive model, and the system noise variance is adaptively determined in infrared object tracking. Infrared objects are represented by the intensity distribution, which is defined by the kernel-based density estimation. By calculating the Bhattacharyya distance between the object reference distribution and the object sample distribution, the observation probability model is constructed. Experimental results show that our method is effective and steady.

Image Processing and Software Simulation

• IMAGE SEGMENTATION BY SPECTRAL CLUSTERING ALGORITHM WITH SPATIAL COHERENCE CONSTRAINTS

  JIA Jian-Hua, JIAO Li-Cheng

  2010,29(1):69-74, DOI:

  Abstract: (10872) HTML (387) PDF (808.83 KKB)(9841)

  Abstract:

  Image segmentation is one of the difficult problems in computer vision research. Recently spectral clustering has a wide application in pattern recognition and image segmentation. Compared with traditional clustering methods, it can cluster samples in any form feature space and has a global optimal solution. Originating from the equivalence between the spectral clustering and weighted kernel K-means, the authors proposed a spectral clustering algorithm with spatial constraints based on the spatially coherent property of images, also named continuous property. The spatially coherent property means that pixels in the neighbor region should share the same label assignment with the centre one with a high probability. The algorithm adds a term of spatial constraints to the objective function of weighted kernel K-means and makes the minimization of the objective function be equivalent to the spectral clustering through approximation. Experimental results show that our proposed algorithm outperforms the traditional spectral clustering in image segmentation.

• INFRARED TARGET EXTRACTION ALGORITHM BY USING PARTICLE SWARM OPTIMIZATION PARTICLE FILTER

  ZHOU Yue, MAO Xiao-Nan

  2010,29(1):63-68, DOI:

  Abstract: (10952) HTML (439) PDF (750.21 KKB)(9235)

  Abstract:

  A novel infrared target extraction algorithm based on particle swarm optimization particle filter(PSOPF) was proposed. The problem of infrared target extraction was analyzed and solved in the view of state estimation. In the framework of particle filter, the threshold state space on the gray-variance weighted information entropy and the grey value of each pixel was based on extraction results evaluation function, which integrated grey, entropy, gradient and spatial distribution of pixels. Finally, the weighted average of all the particles was used as target extraction threshold. The experiment results prove that the proposed algorithm is effective and robust.

• EFFECTS OF APODIZATION FUNCTIONS OF IMAGING FOURIER TRANSFORM SPECTROMETER ON RECONSTRUCTED SPECTRUM

  ZHANG Wen-Juan, ZHANG Bing, ZHANG Xi, GAO Lian-Ru, ZHANG Wei

  2008,27(3):227-233, DOI:

  Abstract: (11369) HTML (435) PDF (1.12 MKB)(8769)

  Abstract:

  随着搭载干涉成像光谱仪HJY20-1-A的我国环境与减灾遥感卫星HJ-1A即将发射,我国干涉光谱成像研究也从实验室开始走向实用化.在干涉光谱成像过程中,切趾函数处理是干涉成像光谱仪光谱复原过程中的一个重要环节,对复原光谱的精度有着极其重要的影响.根据HJY20-1-A的参数设置,文中首先模拟了24种典型地物对应于HJY20-1-A和其它最大光程差设置的干涉成像光谱仪数据,在不同切趾函数作用下的复原光谱,结果表明Hanning函数是其中最有效、最为稳定的切趾函数,同时发现切趾函数的应用虽然可以提高复原光谱的精度,但与真实光谱仍存在一定差距,尤其对应HJY20-1-A,复原光谱的精度更加有限.在以上分析基础上,提出了基于仪器线型函数标准化的光谱复原改进算法,实验结果证实了该方法可以显著提高复原光谱精度,尤其适用于最大光程差较小的空间调制型干涉成像光谱仪.最后,就HJY20-1-A复原光谱对3种典型植被指数求解,进一步证明了该方法的有效性.

• HYPERSPECTRAL REMOTE SENSING IMAGE CLASSIFICATION BASED ON SUPPORT VECTOR MACHINE

  TAN Kun, DU Pei-Jun

  2008,27(2):123-128, DOI:

  Abstract: (2655) HTML (936) PDF (735.00 KKB)(8519)

  Abstract:

  多数传统分类算法应用于高光谱分类都存在运算速度慢、精度比较低和难以收敛等问题.本文从支持向量机基本理论出发建立了一个基于支持向量机的高光谱分类器,并用国产OMIS传感器获得的北京中关村地区高光谱遥感数据进行试验,分析比较了各种SVM核函数进行高光谱分类的精度,以及网格搜寻的方法来确定C和愕闹?结果表明SVM进行高光谱分类时候径向基核函数的分类精度最高,是分类的首选.并且与神经网络径向基分类算法以及常用的最小距离分类算法进行比较,分类的精度远远高于SVM分类算法进行分类的结果.SVM方法在高光谱遥感分类领域能得到广泛的应用.

• IMAGE RETRIEVAL BASED ON IMAGE ENTROPY AND SPATIAL DISTRIBUTION ENTROPY

  SUN Jun-Ding, DING Zhen-Guo, ZHOU Li-Hua

  2005,24(2):135-139, DOI:

  Abstract: (1128) HTML (99) PDF (380.01 KKB)(7641)

  Abstract:

  A new image retrieval algorithm based on image entropy and spatial distribution entropy was presented. At first a more robust method, which can remove the influence of the symmetry of entropy, was proposed to extract the global color feature. Then color spatial distribution entropy vector for each color channel was also introduced to represent the spatial color information. After that, the moments were adopted to reduce the dimension of color spatial distribution entropy. In the end, a low dimensional vector which includes the global and spatial information was used as index for color image retrieval. The experiment results show that the new method gives better performance than color histogram.

• RESEARCH ON ELECTRO-INDUCED BIREFRINGENCE IN CRYSTAL SILICON

  ZHANG Yu-Hong, CHEN Zhan-Guo, JIA Gang, SHI Bao, REN Ce, LIU Xiu-Huan, WU Wen-Qing

  2008,27(3):165-169, DOI:

  Abstract: (7594) HTML (181) PDF (466.11 KKB)(7504)

  Abstract:

  首次测量了硅材料在1.3μm波长处,基于克尔效应和弗朗兹-凯尔迪什效应的电致双折射,进而计算出三阶非线性极化率张量X(3)的分量X(3)xyxy.观测到弗朗兹-凯尔迪什效应引起的折射率变化与入射光的偏振态有关.在实验中,测得了由克尔效应引起的折射率之差为⊿n=5.49×10-16E20,而弗朗兹-凯尔迪什效应引起的折射率之差为⊿n'=2.42×10-16E2.50.

Terahertz and Millimeter Wave Technology

• Design and experimental verification of band-pass frequency selective surface based on metamaterial effective medium theory

  WU Xiang, PEI Zhi-Bin, QU Shao-Bo, XU Zhuo, ZHANG Jie-Qiu, MA Hua, WANG Jia-Fu, WANG Xin-Hua, ZHOU Hang

  2011,30(5):469-474, DOI:

  Abstract: (2271) HTML (131) PDF (1.09 MKB)(6984)

  Abstract:

  By adjusting the effective permittivity of the unit cell, a new method of constructing metamaterial band-pass frequency selective surface was proposed. The effective permittivity of continuous conducting wires is negative below the plasma frequency and thus a stop-band occurs. By combining the continuous conducting wires with cut wires, we realized a one-dimensional frequency selective surface. Both the theory analysis and simulation results demonstrated the facility and feasibility of the method. We also designed a wide-angle and polarization-independent frequency selective surface based on this method. Two samples were fabricated to validate the proposed method; the experiment results were fairly consistent with the simulation results. The proposed method eliminates the complicated calculation and excessive parameter optimization process. It paves a new way of designing frequency selective surfaces and is of important reference values for fabricating THz frequency selective surface as well as multi-band, tunable and miniaturized frequency selective surfaces.

Image Processing and Software Simulation

• HYPERSPECTRAL ANOMALY DETECTION ALGORITHM BASED ON BACKGROUND RESIDUAL ERROR DATA

  LI Jie, ZHAO Chun-Hui, MEI Feng

  2010,29(2):150-151, DOI:

  Abstract: (2352) HTML (62) PDF (571.44 KKB)(6799)

  Abstract:

  In order to overcome the serious background interferences for small target detection of hyperspectral imagery, a nonlinear anomaly detection algorithm based on the background residual error data was proposed. After the background endmembers were extracted, spectral unmixing technique was applied to all mixed spectral pixels to separate target information from complicated background clutter.Then, the unmixing residual error data that included abundant target information was mapped into a high-dimensional feature space by a nonlinear mapping function. Nonlinear information between the spectral bands of hyperspectral imagery was exploited and the anomaly targets could be detected by using RX operator in the feature space. Thus, the ninlinear statistical characteristics between the hyperspectral bands were used effectively on the basis of suppressing the large probability background information. Numerical experiments were conducted on real AVIRIS data to validate the effectiveness of the proposed algorithm. The detection results were compared with those detected by the classical RX algorithm and KRS which did not suppress the backguound information. The results show that the proposed algorithm has better detection performance, lower false alarm probability and lower computational complexity than other detection algorithms.

Infrared Materials and Devices

• Temperature dependent characteristics of HgCdTe variable-area photovoltaic detectors on Si substrates

  ZHANG Shan, HU Xiao-Ning

  2011,30(5):412-414, DOI:

  Abstract: (4976) HTML (160) PDF (704.75 KKB)(6751)

  Abstract:

  The variable-area HgCdTe/Si photovoltaic detector was investigated in this paper. By analyzing the relationship of dark current density (J) and the ratio of perimeter to area (p/A) under different reverse bias, it is indicated that the n-on-p type HgCdTe/Si photovoltaic detector has a significant surface leakage current under larger reverse bias. The minority carrier diffusion length at different temperature can be obtained by fitting the relationship between the product of zero-bias resistance and area (R0A) and p/A. It shows that the minority carrier diffusion length increases with the increase of temperature below 200 K, while the minority carrier diffusion length decreases with the increase of temperature above 200 K. The minority carrier lifetime of Hg-vacancy p-type HgCdTe on Si substrate was calculated from the minority diffusion length at different temperature. It was concluded that the lifetime of HgCdTe/Si minority carrier and its relationship with the temperature is the same as that of HgCdTe/CdZnTe material by comparing the minority carrier lifetime for these two kinds of materials.

Terahertz and Millimeter Wave Technology

• Passive millimeter wave focal plane array imaging technology

  WANG Nan-Nan, QIU Jing-Hui, ZHANG Peng-Yu, DENG Wei-Bo

  2011,30(5):419-424, DOI:

  Abstract: (3296) HTML (195) PDF (1.64 MKB)(6734)

  Abstract:

  Under the background of safety inspection, the key technologies of near-range passive millimeter wave focal plane array imaging are studied. The analysis of the system quasi-optics were carried out using fundamental Gaussian beam method combined with geometrical optics method. A multi-beam wide-angle scanning lens antenna was designed. A new dielectric rod antenna was devised, which is prone to be aligned in close arrays and provide good radiation to the lens. Miniaturized direct-detection radiometers were fabricated with high-sensitive in Ka-band . Experimental results of the 20-channel passive millimeter wave focal plane array imaging system are presented, which can be used to detect hidden objects on human bodies in near range indoors.

• INFLUENCE OF DEPOSITION POWER ON THE COMPOSITION, STRUCTURE AND PROPERTIES OF PZT THIN FILMS PREPARED BY RF SPUTTERING

  LI Xin-Xi 1, LAI Zhen-Quan 1, WANG Gen-Shui 2, SUN Jing-Lan 2 ZHAO Qiang 2, CHU Jun-Hao 2

  2004,23(4):313-316, DOI:

  Abstract: (1347) HTML (109) PDF (520.22 KKB)(6551)

  Abstract:

  用射频(RF)溅射法在镀LaNiO3(LNO)底电极的Si片上沉积PbZr0.52 Ti0.48 O3(PZT)铁电薄膜，沉积过程中基底温度为370℃，然后在大气环境中对沉积的PZT薄膜样品进行快速热退火处理(650℃，5min)．用电感耦合等离子体发射光谱(ICP-AES)测量其组分，X射线衍射(XRD)分析PZT薄膜的结晶结构和取向，扫描电子显微镜(SEM)分析薄膜的表面形貌和微结果，RT66A标准铁电综合测试系统分析Pt／PZT／LNO电容器的铁电与介电特性，结果表明，PZT薄膜的组分、结构和性能都与溅射沉积功率有关．

Image Processing and Software Simulation

• INFRARED IMAGING MODEL FOR SCENE SIMULATION AND ITS VALIDATION

  LI Hong-Ning, BAI Ting-Zhu, CAO Feng-Mei, MA Shuai, XU Kai-Da, YANG Wei-Ping, FENG Jie

  2010,29(1):57-62, DOI:

  Abstract: (2720) HTML (136) PDF (472.80 KKB)(6406)

  Abstract:

  Based on the illumination model which is widely used in computer graphics and the radiance transfer law, a simplified thermal infrared imaging model is derived by: 1) adding the surface temperature distribution and the material parameters to the geometric model, 2) introducing the self emission and the detector property into the Illumination model. Using this model, the ray tracing method is applied to construct an infrared imaging system which can get the synthetic infrared images from any angle of view of the 3D scenes. Three typical 3D scenes are made to validate the infrared imaging model, and the infrared images are calculated to compare and contrast with the real infrared images obtained by a middle infrared band imaging camera. It shows that the thermal infrared imaging model is capable of producing infrared images which are very similar to those received by thermal infrared camera. Quantitative analysis shows that the absolute brightness does not match well, and the reasons are analyzed.

• STUDY ON HIGH RESOLUTION TIME INTERVAL MEASUREMENT MODULE IN PULSED LASER RANGING SYSTEM

  WU Gang, LI Chun-Lai, LIU Yin-Nian, DAI Ning, WANG Jian-Yu

  2007,26(3):213-216221, DOI:

  Abstract: (1976) HTML (213) PDF (268.18 KKB)(6357)

  Abstract:

  The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement. Therefore, a high resolution time interval measurement module was developed. The module is based on the special time-to-digital conversion chip which adopts the delay line interpolation method. The maximum measuring time of the module is 200ms, and the maximum time resolution is 125ps, of which the corresponding distance resolution is 18.75mm. The module is especially suit for the large distance measurement. The hardware and the software of the module as well as the testing results are also presented.

• ANISOTROPIC GAUSSIAN FILTERING FOR INFRARED IMAGE

  WANG Huai-Ye, ZHANG Ke, LI Yan-Jun

  2005,24(2):109-113, DOI:

  Abstract: (1648) HTML (111) PDF (363.60 KKB)(6345)

  Abstract:

  为了在抑制噪声时尽可能保留图像边缘信息，提出一种自适应各向异性高斯滤波器设计方法．该方法由独立强度传播(IDS)模型决定滤波器的长轴尺度，由像素的邻域平滑度决定长短轴的比例，然后根据该处的灰度梯度方向自适应决定各向异性滤波器的长轴方向．仿真实验表明，提出的自适应各向异性滤波器具有很强的噪声抑制和边缘保持能力．

• METHOD ON DESIGNING AND TRAINING OF ARTIFICIAL NEURAL NETWORK BASED ON GENETIC ALGORITHM

  WU Yan, WAN Wei

  2007,26(1):65-68, DOI:

  Abstract: (1123) HTML (98) PDF (183.75 KKB)(6202)

  Abstract:

  A method for designing and training artificial neural network based on genetic algorithm(NNDT) was presented.NNDT trains both architectures and weights of networks simultaneously.The problem that the one-to-one relationship between the topology and the encoding can not be kept was solved effectively.Heuristic method was used to constraint the probability of topology mutation and the trend of the choice of the kind of mutation.Also,the niching mechanism was used to protect the mutation of network topologies.The experiments results show the efficiency and rapidity of NNDT.

Terahertz and Millimeter Wave Technology

• Development and application of the millimeter wave SAR

  WANG Hui, ZHAO Feng-Jun, DENG Yun-Kai

  2015,34(4):452-459, DOI: 10.11972/j.issn.1001-9014.2015.04.013

  Abstract: (2770) HTML (165) PDF (3.92 MKB)(6134)

  Abstract:

  Synthetic aperture radar (SAR) is a microwave remote sensing radar with capability of all-day and all-weather imaging. Millimeter-wave SAR has become important for development of SAR with the advantage of small volume, light weight, and high resolution. The basic principle for high resolution imaging of millimeter-wave SAR is analyzed, and the advantage of millimeter-wave SAR is present. The state-of-art in the development of millimeter-wave SAR technologies and systems are illustrated with some typical millimeter-wave SAR systems. The application prospects, some issues, and future development trend of millimeter-wave SAR are also discussed.