Volume 43,2024 Issue 4

Infrared Materials and Devices

• 1 280×1 024 dual-color mid-wavelength infrared InAs/GaSb superlattice focal plane arrays

  BAI Zhi-Zhong, HUANG Ming, XU Zhi-Cheng, ZHOU Yi, LIANG-Zhao Ming, YAO Hua-Cheng, CHEN Hong-Lei, DING Rui-Jun, CHEN Jian-Xin

  2024,43(4):437-441, DOI: 10.11972/j.issn.1001-9014.2024.04.001

  Abstract: (157) HTML (29) PDF (1.43 MKB)(413)

  Abstract:

  In this paper， we report research results of 1 280×1 024 dual-color mid-wavelength infrared InAs/GaSb superlattice focal plane arrays. The detector structure is PN-NP epitaxial multilayer and the signal is read out by sequential mode. The superlattice structure was grown on GaSb substrate using molecular beam epitaxy （MBE） technology. The respective structures of each absorption region are Mid-Wavelength 1（MW1）： 6 ML （InAs） /7 ML （GaSb） and Mid-Wavelength 2 （MW2）： 9 ML （InAs） /7 ML （GaSb）. The pixel center distance of the detector is 12 μm. At 80 K measurements， the detector has spectral response wavelength of 3-4 μm and 3.8-5.2 μm respectively. The MW1 detector has a peak detectivity of 6.32×10¹¹ cm·Hz^1/2W^-1. The MW2 detector has a peak detectivity of 2.84×10¹¹ cm·Hz^1/2W^-1. Infrared images of both wavebands have been taken using infrared imaging test by adjusting the device voltage bias. It’s the first time that a 1 280 × 1 024 InAs/GaSb Type II superlattice mid-wave length two-color infrared focal plane detector has been reported in China.

• Characterization of 2 μm band soliton optical comb based on silicon nitride microcavity

  CHENG Ru-Min, SUN Jia-Hao, WU Jia-Gui, GUO Deng-Ji, XU Jiao, YANG Jun-Bo, YAN Pei-Guang

  2024,43(4):442-449, DOI: 10.11972/j.issn.1001-9014.2024.04.002

  Abstract: (83) HTML (17) PDF (3.12 MKB)(287)

  Abstract:

  The optical frequency comb （OFC） generation of 2 μm silicon nitride microcavity is investigated. Dispersion modulation of silicon nitride waveguides is carried out by geometrical design. Appropriate bus waveguide dimensions are selected， and the thermal refraction noise of silicon nitride microcavities at different modulation frequencies is discussed by the thermal absorption theory. The nonlinear Schr?dinger equation is used as the basic model to study the evolution of the cavity under different dispersion effects. The numerical results show that silicon nitride is able to observe the hysteretic state transition of the system， i.e.， the relaxation oscillation phenomenon during the transition of the system to the stable domain， more clearly in the 2 μm band. At the same time， the cavity is able to transition to the steady state soliton faster under the action of higher-order dispersion， which provides a scheme to study the respiratory soliton.

• Mid-wavelength infrared nBn photodetectors based on InAs/InAsSb type-II superlattice with an AlAsSb/InAsSb superlattice barrier

  SHAN Yi-Fan, WU Dong-Hai, XIE Ruo-Yu, ZHOU Wen-Guang, CHANG Fa-Ran, LI Nong, WANG Guo-Wei, JIANG Dong-Wei, HAO Hong-Yue, XU Ying-Qiang, NIU Zhi-Chuan

  2024,43(4):450-456, DOI: 10.11972/j.issn.1001-9014.2024.04.003

  Abstract: (106) HTML (21) PDF (1.82 MKB)(310)

  Abstract:

  InAs/InAsSb type-II superlattice （T2SL） materials hold great promise for the development of mid-wavelength infrared photodetectors operating at high temperatures， as they avoid the defects caused by Ga atoms in InAs/GaSb T2SL and exhibit long minority carrier lifetime. To reduce the dark current， minority carrier unipolar barrier structures， such as nBn detectors， are commonly employed. In mid-wavelength infrared InAs/InAsSb T2SL nBn photodetectors， the multielement alloy such as AlAsSb is typically utilized as the barrier layer to block the transport of majority carriers. However， the small valence band offset （VBO） between the barrier and absorption layers leads to the saturation of photocurrent at high bias voltage， resulting in increased dark current. In this work， an AlAsSb/InAsSb T2SL barrier was designed to eliminate the VBO and reduce the bias dependency of quantum efficiency. The results show that the fabricated nBn photodetector exhibits a 50% cutoff wavelength of 4.5 μm at 150 K. The optical response of the photodetector saturates under a small bias of -50 mV， achieving a peak responsivity of 1.82 A/W at 3.82 μm and a quantum efficiency of 58.8%. At 150 K and -50 mV applied bias， the photodetector exhibits a dark current density of 2.01×10^-5 A/cm² and a specific detectivity of 6.47×10¹¹ cm·Hz^1/2/W.

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• Structural design of mid-infrared waveguide detectors based on InAs/GaAsSb superlattice

  PEI Jin-Di, CHAI Xu-Liang, WANG Yu-Peng, ZHOU Yi

  2024,43(4):457-463, DOI: 10.11972/j.issn.1001-9014.2024.04.004

  Abstract: (85) HTML (21) PDF (2.44 MKB)(215)

  Abstract:

  In the realm of near-infrared spectroscopy， the detection of molecules has been achieved using on-chip waveguides and resonators. In the mid-infrared band， the integration and sensitivity of chemical sensing chips are often constrained by the reliance on off-chip light sources and detectors. In this study， we demonstrate an InAs/GaAsSb superlattice mid-infrared waveguide integrated detector. The GaAsSb waveguide layer and the InAs/GaAsSb superlattice absorbing layer are connected through evanescent coupling， facilitating efficient and high-quality detection of mid-infrared light with minimal loss. We conducted a simulation to analyze the photoelectric characteristics of the device. Additionally， we investigated the factors that affect the integration of the InAs/GaAsSb superlattice photodetector and the GaAsSb waveguide. Optimal thicknesses and lengths for the absorption layer are determined. When the absorption layer has a thickness of 0.3 μm and a length of 50 μm， the noise equivalent power reaches its minimum value， and the quantum efficiency can achieve a value of 68.9%. The utilization of waveguide detectors constructed with III-V materials offers a more convenient means of integrating mid-infrared light sources and achieving photoelectric detection chips.

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• Research on silicon avalanche photodetector with wideband response

  PENG Hong-Ling, WEI Jia-Qi, SONG Chun-Xu, WANG Tian-Cai, CAO Peng, CHEN Jian, DENG Jie, ZHUANG Qian-Dong, ZHENG Wan-Hua

  2024,43(4):464-471, DOI: 10.11972/j.issn.1001-9014.2024.04.005

  Abstract: (72) HTML (45) PDF (2.20 MKB)(392)

  Abstract:

  Based on the current application requirements for wideband response photodetectors， we designed a novel silicon avalanche photodetector （Si APD） with high response in a broad spectral range of 250 -1 100 nm and it could achieve efficient detection of ultraviolet， visible and near-infrared light without splicing. The enhancement of silicon on ultraviolet and infrared bands was separately analyzed. This was followed by simulation on the device structure designs using different methods such as back incidence， to improve short wavelength absorption while maintaining a high infrared absorption. The Si APD shows a peak wavelength at around 940 nm and a high photoresponse at 250 nm and 1 100 nm which exceeds 15% of the peak responsivity. This type of device is suitable for multispectral applications and future high-precision detection.

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• Investigation on p-type doping of PBn unipolar barrier InAsSb photodetectors

  ZHANG Jian, CHANG Chao, LI Hong-Fu, SHI Yu-Na, YIN Han-Xiang, LI Yan-Hui, YUE Biao, WANG Hai-Peng, YAN Chang-Shan, DAI Xin-Ran, DENG Gong-Rong, KONG Jin-Cheng, ZHAO Peng, ZHAO Jun

  2024,43(4):472-478, DOI: 10.11972/j.issn.1001-9014.2024.04.006

  Abstract: (64) HTML (11) PDF (3.86 MKB)(258)

  Abstract:

  The lattice-matched XBn structures of InAsSb， grown on GaSb substrates， exhibit high crystal quality， and can achieve extremely low dark currents at high operating temperatures （HOT）. Its superior performance is attributed to the unipolar barrier， which blocks the majority carriers while allowing unhindered hole transport. To further explore the energy band and carrier transport mechanisms of the XBn unipolar barrier structure， this paper systematically investigates the influence of doping on the dark current， photocurrent， and tunneling characteristics of InAsSb photodetectors in the PBn structure. Three high-quality InAsSb samples with unintentionally doped absorption layers （AL） were prepared， with varying p-type doping concentrations in the GaSb contact layer （CL） and the AlAsSb barrier layer （BL）. As the p-type doping concentration in the CL increased， the device’s turn-on bias voltage also increased， and p-type doping in the BL led to tunneling occurring at lower bias voltages. For the sample with UID BL， which exhibited an extremely low dark current of 5×10^-6 A/cm². The photocurrent characteristics were well-fitted using the back-to-back diode model， revealing the presence of two opposing space charge regions on either side of the BL.

• A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

  CHEN Ze-Ji, HUANG You-Wen, PU En-Xiang, XIAO Hui-Shan, XU Shi-Chun, QIN Qiang, KONG Jin-Cheng

  2024,43(4):479-489, DOI: 10.11972/j.issn.1001-9014.2024.04.007

  Abstract: (103) HTML (15) PDF (2.76 MKB)(283)

  Abstract:

  A medium wave （MW） 640×512 （25 μm） Mercury Cadmium Telluride （HgCdTe） polarimetric focal plane array （FPA） was demonstrated. The micro-polarizer array （MPA） has been carefully designed in terms of line grating structure optimization and crosstalk suppression. A monolithic fabrication process with low damage was explored， which was verified to be compatible well with HgCdTe devices. After monolithic integration of MPA， NETD < 9.5 mK was still maintained. Furthermore， to figure out the underlying mechanism that dominated the extinction ratio （ER）， specialized MPA layouts were designed， and the crosstalk was experimentally validated as the major source that impacted ER. By expanding opaque regions at pixel edges to 4 μm， crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%， and promising ERs ranging from 17.32 to 27.41 were implemented.

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• Application of principal component analysis and clustering methods in the discrimination of parameters in HgCdTe crystals

  WU Jia-Hao, QIAO Hui, LI Xiang-Yang

  2024,43(4):490-496, DOI: 10.11972/j.issn.1001-9014.2024.04.008

  Abstract: (59) HTML (22) PDF (2.16 MKB)(222)

  Abstract:

  A method for selecting parameters in HgCdTe crystals has been proposed， utilizing Principal Component Analysis （PCA） and clustering methods， with the establishment of a data model for screening the parameters of HgCdTe crystals. Within the model， the initial crystal data undergoes a cleaning and analysis process. PCA is employed for dimensionality reduction， and the Density-Based Spatial Clustering of Applications with Noise （DBSCAN） algorithm is used to identify the densest regions within the crystal data. Furthermore， the high-performance chip data， obtained after post-processing， is utilized to fit boundary ellipses for high-quality HgCdTe crystal parameters. These ellipses act as criteria for identifying high-quality crystals. The model is capable of generating crystal ratings based on input electrical and optical parameters with a coverage rate exceeding 90%.

• Optical facet coatings for high-performance LWIR quantum cascade lasers at λ ∼ 8.5 µm

  MA Yuan, LIN Yu-Zhe, WAN Chen-Yang, WANG Zi-Xian, ZHOU Xu-Yan, ZHANG Jin-Chuan, LIU Feng-Qi, ZHENG Wan-Hua

  2024,43(4):497-502, DOI: 10.11972/j.issn.1001-9014.2024.04.009

  Abstract: (84) HTML (18) PDF (2.99 MKB)(288)

  Abstract:

  We report on the performance improvement of long-wave infrared quantum cascade lasers （LWIR QCLs） by studying and optimizing the anti-reflection （AR） optical facet coating. Compared to the Al₂O₃ AR coating， the Y₂O₃ AR coating exhibits higher catastrophic optical mirror damage （COMD） level， and the optical facet coatings of both material systems have no beam steering effect. A 3-mm-long， 9.5-μm-wide buried-heterostructure （BH） LWIR QCL of λ ~ 8.5 μm with Y₂O₃ metallic high-reflection （HR） and AR of ~ 0.2% reflectivity coating demonstrates a maximum pulsed peak power of 2.19 W at 298 K， which is 149% higher than that of the uncoated device. For continuous-wave （CW） operation， by optimizing the reflectivity of the Y₂O₃ AR coating， the maximum output power reaches 0.73 W， which is 91% higher than that of the uncoated device.

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Terahertz and Millimeter Wave Technology

• The research progress of millimeter-wave power applications （invited）

  LU Dun, FU Wen-Jie, MIKHAIL Glyavin, TANG Xiang-Wei, HU Min, LIU Sheng-Gang

  2024,43(4):503-519, DOI: 10.11972/j.issn.1001-9014.2024.04.010

  Abstract: (94) HTML (19) PDF (6.59 MKB)(345)

  Abstract:

  In general， all known applications of high-power microwaves directly use energy to interact with matter. In recent years， with the development of powerful millimeter-wave radiation sources， microwave technology has gradually shifted towards the millimeter-wave frequency band. Due to the wavelength of radiation， millimeter waves have several unique characteristics， which allow for both the active development of existing technologies and the creation of new ones that require high power or radiation energy. This article provides an overview of research on the application of millimeter waves to solve problems in physics， material science， biomedicine， and others， including heating and diagnostics of thermonuclear plasma， processing and analysis of materials， biological effects， etc. The main difficulties arising in the implementation of the described tasks are presented， and the future development is also prospected.

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• An improved ASM-HEMT model for kink effect on GaN devices

  WANG Shuai, CHENG Ai-Qiang, GE Chen, CHEN Dun-Jun, LIU Jun, DING Da-Zhi

  2024,43(4):520-525, DOI: 10.11972/j.issn.1001-9014.2024.04.011

  Abstract: (47) HTML (15) PDF (2.20 MKB)(269)

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  With the analysis of experiment and theory on GaN HEMT devices under DC sweep， an improved model for kink effect based on advanced SPICE model for high electron mobility transistors （ASM-HEMT） is proposed， considering the relationship between the drain/gate-source voltage and kink effect. The improved model can not only accurately describe the trend of the drain-source current with the current collapse and kink effect， but also precisely fit different values of drain-source voltages at which the kink effect occurs under different gate-source voltages. Furthermore， it well characterizes the DC characteristics of GaN devices in the full operating range， with the fitting error less than 3%. To further verify the accuracy and convergence of the improved model， a load-pull system is built in ADS. The simulated result shows that although both the original ASM-HEMT and the improved model predict the output power for the maximum power matching of GaN devices well， the improved model predicts the power-added efficiency for the maximum efficiency matching more accurately， with 4% improved.

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• The physical model， structural fabrication， and DC testing of lateral gate transistor terahertz detectors

  KANG Ya-Ru, DONG Hui, LIU Jing, HUANG Zhen, LI Zhao-Feng, YAN Wei, WANG Xiao-Dong

  2024,43(4):526-532, DOI: 10.11972/j.issn.1001-9014.2024.04.012

  Abstract: (57) HTML (10) PDF (1.33 MKB)(221)

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  For the high-electron-mobility transistor （HEMT） terahertz detector with a side-gate structure， a physical model for DC transport and terahertz detection of the device was constructed. Using a self-alignment process， well-shaped and reliable contacts for the side-gate structure were successfully fabricated， effectively solving contact issues between the dual gates and the mesa. Ultimately， terahertz detectors with different gate widths （200 nm， 800 nm， and 1400 nm） of side-gate GaN/AlGaN HEMTs were obtained. DC tests revealed a clear linear relationship between the gate widths of different devices and their threshold voltages， confirming the DC transport model of the side-gate HEMT terahertz detector. These results provide experimental verification and guidance for the theoretical model of the complete side-gate HEMT terahertz detector， offering significant support for the development of side-gate HEMT terahertz detectors.

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• Preparation of flexible low-loss ABS/Ag-coated terahertz hollow waveguide by plasma treatment and study on its transmission reliability

  LIU Sheng, SHEN Yuan-Jie, HOU Guang-Ning, ZHA Zhi-Peng, ZHU Yi-Zhen, YU Shuo-Ying, ZHANG Qing-Tian, ZHAO Qiang, LIU Shao-Hua, JING Cheng-Bin, CHU Jun-Hao

  2024,43(4):533-540, DOI: 10.11972/j.issn.1001-9014.2024.04.013

  Abstract: (46) HTML (15) PDF (2.05 MKB)(237)

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  The performance of ABS/Ag-coated terahertz hollow waveguide （HWG） was improved through plasma treatment of the ABS structural tube. The adhesion of the silver （Ag） film to the ABS tube was enhanced from level 5 to level 2 after plasma treatment. The 4.2 mm bore waveguide sample treated with plasma has a more uniform and denser silver film than the untreated sample， which contributes to the reduction of transmission losses from 0.72 dB/m to 0.70 dB/m at 0.3 THz and 1.47 dB/m to 1.44 dB/m at 0.1 THz， respectively. After 200 hours of hydrothermal aging and 16 cycles of high and low temperature cycling testing， the straight loss of the HWG sample treated with plasma increased by less than 0.1 dB/m， while the untreated sample underwent an increase of more than 1.0 dB/m. The results indicate that the ABS/Ag-coated HWG fabricated by plasma treatment has lower loss， higher reliability and better anti-aging performance compared with the untreated sample. It can be potentially used for establishment of next-generation communication， sensing， and THz imaging systems.

• Terahertz imaging super-resolution algorithm based on Hilbert spatial curve filling

  YANG Mo-Xuan, ZHAO Yuan-Meng, LIU Hao-Xin, LIU Yi, WU You, ZHANG Cun-Lin

  2024,43(4):541-550, DOI: 10.11972/j.issn.1001-9014.2024.04.014

  Abstract: (51) HTML (16) PDF (1.78 MKB)(226)

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  The performance of radiation sources and detectors currently limits terahertz imaging technology， which still requires further improvement in terms of detail resolution， imaging speed， and noise suppression. This paper proposes a terahertz image super-resolution algorithm based on spatial curve filling. The ViT （Vision Transformer） structure backbone network is utilized to extract terahertz image features through an attention mechanism. A Hilbert spatial curve is constructed to reconstruct the image according to the feature map using the curve filling method. Lightweight one-dimensional convolution processing is used for reconstructing image features， while inverse transformation of reconstructed maps restores the image''s spatial structure. Finally， pixel reorganization enables up sampling to obtain an output image with enhanced object contour and details. Experimental results show that compared with conventional ViT structures， this proposed method improves Peak Signal-to-Noise Ratio （PSNR） by 0.81 dB and Structural Similarity Index （SSIM） by 0.007 4， which effectively inhibits the noise influence on texture and significantly improves the resolution and image quality.

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• Simulation analysis of radiation terahertz wave characteristics of photoconductive antenna materials

  HOU Lei, WU Xiao-Bo, YANG Lei, SHI Wei, HANG Yu-Hua

  2024,43(4):551-556, DOI: 10.11972/j.issn.1001-9014.2024.04.015

  Abstract: (61) HTML (11) PDF (1.17 MKB)(327)

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  The photoconductive antenna is a kind of widely used broadband terahertz （THz） radiation source in THz time-domain spectroscopy systems， and the substrate material of the antenna is crucial for the characteristics of generated THz wave. The widely used photoconductive antenna material is the second-generation semiconductor of GaAs， while the third-generation semiconductor has a larger band gap， which is more advantageous for improving the power of THz wave from photoconductive antenna. In this work， the current surge model of large-aperture photoconductive antennas was used to simulate the characteristics of THz waves radiated by the photoconductive antenna made from commonly used SI-GaAs and LT-GaAs， and the third-generation semiconductors （ZnSe， GaN， SiC） that are expected to be used in the future for photoconductive antennas. The results show that under the same bias electric field and their respective highest pump laser flux， LT-GaAs antenna generates THz waves with the highest amplitude and widest frequency. The photoconductive antenna made by the third-generation semiconductor materials can withstand higher bias electric fields， and the intensity of radiated THz waves is much greater than that from GaAs antennas under their respective maximum bias electrical fields. This work provides theoretical guidance for the development of new third-generation semiconductor photoconductive antennas.

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Infrared Photoelectric Technology and Application

• Characteristic analysis of 1.06 μm long-cavity diode lasers based on asymmetric waveguide structures

  ZHAO Ren-Ze, GAO Xin, FU Ding-Yang, ZHANG Yue, SU Peng, BO Bao-Xue

  2024,43(4):557-562, DOI: 10.11972/j.issn.1001-9014.2024.04.016

  Abstract: (85) HTML (14) PDF (1.39 MKB)(221)

  Abstract:

  In long-cavity edge-emitting diode lasers， longitudinal spatial hole burning （LSHB）， two-photon absorption （TPA） and free carrier absorption （FCA） are among the key factors that affect the linear increase in output power at high injection currents. In this paper， a simplified numerical analysis model is proposed for 1.06 μm long-cavity diode lasers by combining TPA and FCA losses with one-dimensional （1D） rate equations. The effects of LSHB， TPA and FCA on the output characteristics are systematically analyzed， and it is proposed that adjusting the front facet reflectivity and the position of the quantum well （QW） in the waveguide layer can improve the front facet output power.

• Miniaturized microchip array passive Q-switched solid-state laser

  WANG Zhen, LI Li-Guang, ZHAO Bai-Qing, LI Jia-Geng, HAN Qin

  2024,43(4):563-571, DOI: 10.11972/j.issn.1001-9014.2024.04.017

  Abstract: (58) HTML (11) PDF (1.53 MKB)(246)

  Abstract:

  To address the spatial constraints in unmanned aerial vehicle target detection systems， a scheme for a multi-beam scanning passive Q-switched microchip array solid-state laser is proposed. This system utilizes a six-core semiconductor laser array to compactly pump a strip-shaped Nd：YAG/Cr⁴⁺：YAG bonded crystal. At a pumping power of 1.6 W per path， it generates six output laser beams with a wavelength of 1 064.4 nm， pulse width of 2.4 ns， beam quality of 1.39， peak power of 3.75 kW， and a repetition frequency up to 22 kHz. The entire system''s volume is only 2 cm×2 cm ×1.5 cm， and achieves simultaneous output of six laser paths. The study investigated the impact mechanism of the initial transmittance of the Q-switching crystal and the reflectivity of the output mirror on the laser pulse repetition frequency and peak power， with a particular focus on the uniformity of the laser output from the pump source cores. The feasibility of using a single laser-bonded crystal to produce multiple narrow pulse laser beams in the nanosecond range was experimentally verified. The research results demonstrate the miniaturized structure''s ability to achieve multi-beam emission from a passive Q-switched solid-state laser， providing insights for the miniaturization and integration of laser sources in detection systems.

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Image Processing and Software Simulation

• Modified multiple-component scattering power decomposition for PolSAR data based on eigenspace of coherency matrix

  ZHANG Shuang, WANG Lu, WANG Wen-Qing

  2024,43(4):572-581, DOI: 10.11972/j.issn.1001-9014.2024.04.018

  Abstract: (59) HTML (14) PDF (1.82 MKB)(223)

  Abstract:

  A modified multiple-component scattering power decomposition for analyzing polarimetric synthetic aperture radar （PolSAR） data is proposed. The modified decomposition involves two distinct steps. Firstly， eigenvectors of the coherency matrix are used to modify the scattering models. Secondly， the entropy and anisotropy of targets are used to improve the volume scattering power. With the guarantee of high double-bounce scattering power in the urban areas， the proposed algorithm effectively improves the volume scattering power of vegetation areas. The efficacy of the modified multiple-component scattering power decomposition is validated using actual AIRSAR PolSAR data. The scattering power obtained through decomposing the original coherency matrix and the coherency matrix after orientation angle compensation is compared with three algorithms. Results from the experiment demonstrate that the proposed decomposition yields more effective scattering power for different PolSAR data sets.

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• Research on fast detection method of infrared small targets under resource-constrained conditions

  ZHANG Rui, LIU Min, LI Zheng

  2024,43(4):582-587, DOI: 10.11972/j.issn.1001-9014.2024.04.019

  Abstract: (131) HTML (37) PDF (1.37 MKB)(215)

  Abstract:

  Infrared small target detection is a common task in infrared image processing. Under limited computational resources. Traditional methods for infrared small target detection face a trade-off between the detection rate and the accuracy. A fast infrared small target detection method tailored for resource-constrained conditions is proposed for the YOLOv5s model. This method introduces an additional small target detection head and replaces the original Intersection over Union （IoU） metric with Normalized Wasserstein Distance （NWD）， while considering both the detection accuracy and the detection speed of infrared small targets. Experimental results demonstrate that the proposed algorithm achieves a maximum effective detection speed of 95 FPS on a 15 W TPU， while reaching a maximum effective detection accuracy of 91.9 AP@0.5， effectively improving the efficiency of infrared small target detection under resource-constrained conditions.

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红外材料与器件

• Infrared aircraft few-shot classification method based on cross-correlation network

  HUANG Zhen, ZHANG Yong, GONG Jin-Fu

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

  Abstract: (48) HTML (0) PDF (1.35 MKB)(25)

  Abstract:

  In response to the scarcity of infrared aircraft samples and the tendency of traditional deep learning to overfit， a few-shot infrared aircraft classification method based on cross-correlation networks is proposed. This method combines two core modules： a simple parameter-free self-attention and cross-attention. By analyzing the self-correlation and cross-correlation between support images and query images， it achieves effective classification of infrared aircraft under few-shot conditions. The proposed cross-correlation network integrates these two modules and is trained in an end-to-end manner. The simple parameter-free self-attention is responsible for extracting the internal structure of the image while the cross-attention can calculate the cross-correlation between images further extracting and fusing the features between images. Compared with existing few-shot infrared target classification models， this model focuses on the geometric structure and thermal texture information of infrared images by modeling the semantic relevance between the features of the support set and query set， thus better attending to the target objects. Experimental results show that this method outperforms existing infrared aircraft classification methods in various classification tasks， with the highest classification accuracy improvement exceeding 3%. In addition， ablation experiments and comparative experiments also prove the effectiveness of the method.

• A HgTe/ZnO Quantum Dots Vertically Stacked Heterojunction Low dark current Photodetector

  Huang Xinning, Jiang Tengteng, Di Yunxiang, Xie Maobin, Guo Tianle, Liu Jingjing, Wu Binmin, Shi Jingmei, Qin Qiang, Deng Gongrong, Chen Yan, Lin Tie, Shen Hong, Meng Xiangjian, Wang Xudong, Chu Junhao, Ge Jun, Wang Jianlu

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

  Abstract: (178) HTML (0) PDF (1.35 MKB)(48)

  Abstract:

  Colloidal quantum dots （CQDs） are affected by the quantum confinement effect， which makes their bandgap tunable. This characteristic allows these materials to cover a broader infrared spectrum， providing a cost-effective alternative to traditional infrared detector technology. Recently， thanks to the solution processing properties of quantum dots and their ability to integrate with silicon-based readout circuits on a single chip， infrared detectors based on HgTe CQDs have shown great application prospects. However， facing the challenges of vertically stacked photovoltaic devices， such as barrier layer matching and film non-uniformity， most devices integrated with readout circuits still use a planar structure， which limits the efficiency of light absorption and the effective separation and collection of photo-generated carriers. Here， by synthesizing high-quality HgTe CQDs and precisely controlling the interface quality， we have successfully fabricated a photovoltaic detector based on HgTe and ZnO QDs. At a working temperature of 80 K， this detector achieved a low dark current of 5.23×10^-9 A cm^-2， a high rectification ratio， and satisfactory detection sensitivity. This work paves a new way for the vertical integration of HgTe CQDs on silicon-based readout circuits， demonstrating their great potential in the field of high-performance infrared detection.

• Study of time and frequency domain characteristics of a quasi-continuous 2 μm thulium-doped fiber laser

  MEI Xue-Han, CHEN Xiang, XU Gang, YANG Yuan-Zhong, ZHANG Zhong, LEI Cheng, LI Sheng, WANG Xing-Huan, WANG Du

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

  Abstract: (51) HTML (0) PDF (947.47 KKB)(100)

  Abstract:

  Lasers near the wavelength of 2 μm are located in the atmospheric transmission window and the strong absorption peak of water， and have important applications in medicine， LIDAR， material processing， and as pump sources for mid-infrared lasers. The thulium-doped fiber laser （TDFL） stands out as a critical light source capable of delivering high power outputs at this wavelength. In this paper， to address the problems of relaxation oscillation and inter-modal four-wave mixing in quasi-continuous wave （QCW） TDFL， the time and frequency-domain output characteristics of the laser are optimized by increasing the bias current， optimizing the length of the gain fiber， and changing the diameter of the fiber coiling， etc. The effects of different gain fiber structures on the fiber transmission modes are also investigated. The developed QCW-TDFL achieves a peak power of 894 W and an average power of 89.4 W at a central wavelength of 1939.2 nm with a pulse width of 100 μs， a repetition frequency of 1 kHz and a duty cycle of 10%， and obtains stable and controllable pulse output waveforms and spectral characteristics.

图像处理及软件仿真

• A lightweight dark object detection network on infrared images

  Li Zhaoxu, Xu Qingyu, An Wei, He Xu, Guo Gaowei, Li Miao, Ling Qiang, Wang Longguang, Xiao Chao, Lin Zaiping

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

  Abstract: (89) HTML (0) PDF (1.24 MKB)(84)

  Abstract:

  Small target detection has been a classic research topic in the field of infrared image processing, and the objects are usually brighter than the local background. However, in some scenarios, the target brightness may be lower than the background brightness. For example, the civil airplanes usually have low-temperature skin when cruising, appearing as dark points on medium spatial resolution thermal infrared satellite images. There are few features of these objects, so the current detection networks are redundant. Hence, authors proposed a lightweight dark object detection network, AirFormer. It only has 37.1K parameters and 46.2M floating-point operations on a 256×256 image. Considering the lack of infrared dark object detection dataset, authors analyzed the characteristics of airplanes on thermal infrared satellite images, and then developed a simulated flying aircraft detection dataset called IRAir. AirFormer achieves 71.0% at recall and 82.6% at detection precision on the IRAir dataset. In addition, after training on simulated data, AirFormer has achieved detection of real flying airplanes on the thermal infrared satellite images.

红外材料与器件

• The Research on Aircraft Altitude Estimate Method Based on Multispectral Feature Matching in Thermal Infrared

  Yang Lifeng, Chen Zhuo, Chen Fansheng, WangJianyu

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

  Abstract: (74) HTML (0) PDF (1.36 MKB)(42)

  Abstract:

  The acquisition of aircraft altitude information is crucial for the aviation safety and traffic control applications. Infrared remote sensing technology can accurately measure the thermal radiation information of targets，which means the potential for quantitative observation of certain characteristics of aircraft target. A method for estimating the altitude of airborne targets based on infrared multi-channel feature matching is proposed in this paper.Firstly， a thermal infrared radiation characteristic observation model of aircraft is established， which based on the thermal infrared radiation characteristics of large aircraft and atmospheric radiative transfer models. Secondly， based on the observation model， a spectral database of aircrafts at different altitudes and flight states under different atmospheric condition can be obtained by simulating. Thirdly， target spectral information can be extracted from remote sensing images and the altitude information can be estimated with using spectral angle matching （SAM）. Finally， verification and analysis were completed using simulation data and SDGSAT-1 in-orbit data. The results indicate that the proposed method can achieve kilometer-level estimation accuracy for aircraft at cruising altitude. This method provides a new solution for estimating the altitude of aircraft and has important application potential.

红外及光电技术与应用

• Wideband and High Power 3D Heterogeneous Integration Photoreceiver

  XU Xiangqian, GONG Guangyu, SUN Lei, LI Yu, Kang Xiaochen, LI Simin, PAN Shilong

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

  Abstract: (63) HTML (0) PDF (832.61 KKB)(12)

  Abstract:

  In this study， we present an innovative three-dimensional （3D） heterogeneously integrated photoreceiver， which is optimized for analog microwave optical links that demand both wide bandwidth and high input optical power. The key of this design is the uni-traveling-carrier photodiode （UTC-PD）， which has been flip-chip integrated onto a microwave integrated circuit submount. This integration approach enhances the photoreceiver"s overall performance， making it ideally suitful for applications requiring wide bandwidth and high power handling capabilities. The material doping and epitaxial processes of the UTC photodiode were optimized to augment its power endurance. Meanwhile， the responsivity of the photodiode was improved through the adoption of an integrated back-illuminated lens complemented by the addition of a metallic reflective layer. By establishing a precise model of the photodiode， we have refined the bandwidth characteristics of the photoreceiver using impedance compensation and broadband matching circuit design techniques. Flip-chip bonding the photodiode chip onto the microwave integrated circuit chip has substantially mitigated the impact of interconnect circuits on high-frequency performance. Furthermore， the thermal conductivity and high-power resilience of the detector chip were enhanced via gold-tin alloy micro-bump interconnections and the design of a high thermal conductivity substrate layer. The three-dimensional heterogeneous integrated photoreceiver features a 1-dB bandwidth of 42 GHz， an RF return loss exceeding 11 dB， a responsivity surpassing 0.85 A/W， a dark current below 50 nA， and a saturated input optical power of over 120 mW.By leveraging the distinctive properties of the UTC-PD， our three-dimensional （3D） heterogeneous integrated photoreceiver design achieves superior efficiency and responsiveness， positioning it as a leading solution for cutting-edge microwave photonics applications.

红外材料与器件

• Research on highly sensitive infrared imaging detection technology based on linear avalanche device

  Lin Changqing, Zhou Shuangxi, Li Lufang, Liu Gaorui, Sun Haibin, Zhang Yu, Lin Jiamu, Sun Shengli

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

  Abstract: (67) HTML (0) PDF (2.11 MKB)(27)

  Abstract:

  With the development of remote sensing technology， the detection sensitivity of infrared system is increasingly required. The infrared imaging detection technology based on linear avalanche device can effectively improve the detection sensitivity in high frame frequency applications. Based on the short-wave infrared linear avalanche detector assembly of 512X512， a small-aperture and lightweight infrared imaging system is designed and its performance is tested under low reverse bias. The test results show that the increase of SNR of the imaging system based on the linear avalanche infrared detector is basically linear with the multiplication factor M under short integration time， and the SNR of the system is 3 times that of the traditional camera of the same caliber.

• Synchronous Object Detection and Matching Network Based on Infrared Binocular Vision

  ZENG Chang-Wen, Yang Zhi-Yu, DAI Zuo-Xiao, GU Ming-Jian

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

  Abstract: (54) HTML (0) PDF (1.89 MKB)(26)

  Abstract:

  The three-dimensional perception of road objects in challenging environments is crucial for the development of autonomous vehicles capable of operating in all conditions， at all hours. Infrared binocular vision mimics the human binocular system， facilitating stereoscopic perception of objects in challenging conditions such as dim or zero-light environments. The core technology for stereoscopic perception in binocular vision systems lies in accurate object detection and matching. To streamline the complex sequence of object detection and matching procedures， a synchronous object detection and matching network （SODMNet） is proposed， which is capable of synchronous detection and matching of infrared objects. SODMNet innovatively combines a object detection network with a object matching module， leveraging the deep features from the classification and regression branches as inputs for the object matching module. By concatenating these features with relative position encodings from the feature maps and processing them through a convolutional network， the network generates feature descriptors for the left and right images. The object matching is then achieved by calculating the Euclidean distances between these descriptors， thus facilitating synchronous object detection and matching in binocular vision. In addition， a novel nighttime infrared binocular dataset， annotated with targets such as pedestrians and vehicles， is created to support the development and evaluation of the proposed network. Experimental results indicate that SODMNet achieves a significant improvement of over 84.9% in object detection mean average precision （mAP） on this dataset， with a object matching average precision （AP） of 0.5777. These results demonstrate that SODMNet is capable of high-precision， synchronized object detection and matching in infrared binocular vision， marking a significant advancement in the field.

• Dual-band narrowband thermal emitter designed based on multi-objective particle swarm optimization

  QIU Qianli, ZHANG Jinguo, ZHOU Dongjie, TAN Chong, SUN Yan, HAO Jiaming, DAI

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

  Abstract: (43) HTML (0) PDF (1.26 MKB)(17)

  Abstract:

  Dual-band thermal emitters with narrow bandwidths are important in various applications in the infrared field， such as in infrared sensing and infrared imaging. However， conditions for narrowband emission in different wavelengths can conflict with each other， making it difficult to achieve dual-band emitter. In this paper， a new type of lithography-free infrared dual-band thermal emitter is proposed， which consists of alternately deposited Ge and YbF₃ films on Al films. The narrowband emission characteristics stem from the Tamm plasmon polaritons （TPP） that can be excited by the distributed Bragg reflector and the Al substrate under certain conditions. The geometric parameters are optimized using multi-objective particle swarm optimization. The experiment results confirm that dual-band emitter can simultaneously exhibit narrowband emitter characteristics in both mid-wave infrared （MWIR） and long-wave infrared （LWIR） regions. The proposed method can be used in the design of multi-band emitssion modulation applications， which can be applied in the fields of multi-gas sensing and multi-band infrared camouflage.

• Infrared spectroscopic analysis of O-H bond dynamics in one-dimensional confined water and bulk water

  ZHANG Lei, Wang Tian-Qi, FAN Yan-Ping

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

  Abstract: (65) HTML (0) PDF (1.08 MKB)(216)

  Abstract:

  In sub nanometer carbon nanotubes， water exhibits unique dynamic characteristics， and in the high-frequency region of the infrared spectrum， where the stretching vibrations of the internal oxygen-hydrogen （O-H） bonds are closely related to the hydrogen bonds （H-bonds） network between water molecules. Therefore， it is crucial to analyze the relationship between these two aspects. In this paper， the infrared spectrum and motion characteristics of the stretching vibrations of the O-H bonds in one-dimensional confined water （1DCW） and bulk water （BW） in （6， 6） single-walled carbon nanotubes （SWNT） are studied by molecular dynamics simulations. The results show that the stretching vibrations of the two O-H bonds in 1DCW exhibit different frequencies in the infrared spectrum， while the O-H bonds in BW display two identical main frequency peaks. Further analysis using the spring oscillator model reveals that the difference in the stretching amplitude of the O-H bonds is the main factor causing the change in vibration frequency， where an increase in stretching amplitude leads to a decrease in spring stiffness and， consequently， a lower vibration frequency. A more in-depth study found that the interaction of H-bonds between water molecules is the fundamental cause of the increased stretching amplitude and decreased vibration frequency of the O-H bonds. Finally， by analyzing the motion trajectory of the H atoms， the dynamic differences between 1DCW and BW are clearly revealed. These findings provide a new perspective for understanding the behavior of water molecules at the nanoscale and are of significant importance in advancing the development of infrared spectroscopy detection technology.

图像处理及软件仿真

• Infrared Person Re-Identification Model Based on Guided Attention at Key Points of Model Human Body

  YU Peng, TIAN Xiao-Jian, PIAO Yan

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

  Abstract: (52) HTML (0) PDF (696.13 KKB)(177)

  Abstract:

  Person Re-Identification is the task of retrieving a specified target from multiple data sources. The difference between infrared （IR） and visible light （VIS） images is large， and cross-modal retrieval of visible light and infrared images is one of the main challenges. In order to have the same retrieval ability even in low light or at night， the judgment needs to be achieved by combining cross-modal modeling of infrared images. In this paper， we propose a new method of guiding attention through human keypoints， where global features are split into local features by keypoint guidance， and then the original model is retrained with the generated local masks to strengthen the attention to different local information. Using this method， the model can better understand and utilize the key regions in the image， thus improving the accuracy of the Person Re-Identification task.

红外及光电技术与应用

• High-precision spot centroid positioning of high-frame-rate short-wave infrared images for satellite laser communication

  FU Peng, HE Dao-Gang, LIU Jun, WANG Yue-Ming

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

  Abstract: (171) HTML (0) PDF (1.80 MKB)(298)

  Abstract:

  The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction. In satellite laser communication systems， the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation. However， there are strong non-uniformity and blind pixels in the short-wave infrared image， which makes the image distorted and leads to the decrease of spot centroid positioning accuracy. Therefore， the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance. A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two， further model-based localization error simulations are performed， and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector. The experimental results show that the non-uniformity of the corrected image is reduced from 7% to 0.6%， the blind pixels rejection rate reaches 100%， the frame rate can be up to 2000 Hz， and the spot centroid localization accuracy is as high as 0.1 pixel point， which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.

红外材料与器件

• The effect of doping on the optical and physicochemical properties of YbF₃ and its application in infrared coatings

  MA Qiu-Jing, DUAN Wei-Bo, YU Tian-Yan, LI Da-Qi, YU De-Ming, LIU Bao-Jian, ZHUANG Qiu-Hui, LIU Ding-Quan

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

  Abstract: (204) HTML (0) PDF (2.94 MKB)(328)

  Abstract:

  The effects of calcium fluoride （CaF₂） doping on the optical and physical and chemical properties of Ytterbium fluoride （YbF₃） materials were studied. Pure YbF₃ thin films and YbF₃ thin films doped with different proportions of CaF₂ were deposited by electron beam and thermal evaporation， respectively. The characteristics of single layer were measured by spectrometer， stress measurement system， X-ray Diffraction （XRD）， Atomic Force Microscope （AFM） and other measuring devices. The optical constants were fitted by the classical Lorentz oscillator model. The results show that the single-layer film with better optical and physical and chemical properties is obtained by electron beam deposition， in the condition of 1% CaF₂ doping. A long-wave infrared anti-reflection multi-layer sample was designed and fabricated and its spectrum and reliability test were carried out. The results show that its transmittance in the long-wave infrared region is as high as 99%， and the reliability meets the requirements of space application.

• The influence of V/III ratio on electron mobility of the InAsxSb1-x layers grown on GaAs substrate by molecular beam epitaxy

  ZHANG Jing, YANG Zhi, ZHENG Li-Ming, ZHU Xiao-Juan, WANG Ping, YANG Lin

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

  Abstract: (80) HTML (0) PDF (1.78 MKB)(256)

  Abstract:

  This paper discusses the influence of Sb/In ratio on the transport properties and crystal quality of the 200 nm InAsxSb1-x thin film. The Sb content of InAsxSb1-x thin film in all samples was verified by HRXRD of the symmetrical 004 reflections and asymmetrical 115 reflections. The calculation results show that the Sb component was 0.6 in the InAsxSb1-x thin film grown under the conditions of Sb/In ratio of 6 and As/In ratio of 3, which has the highest electron mobility (28560 cm2/V·s) at 300 K. At the same time, the influence of V/III ratio on the transport properties and crystal quality of Al0.2In0.8Sb/InAsxSb1-x quantum well heterostructures also has been investigated. As a result, the Al0.2In0.8Sb/InAs0.4Sb0.6 quantum well heterostructure with a channel thickness of 30 nm grown under the conditions of Sb/In ratio of 6 and As/In ratio of 3 has a maximum electron mobility of 28300 cm2/V·s and a minimum RMS roughness of 0.68 nm. Through optimizing the growth conditions, our samples have higher electron mobility and smoother surface morphology.

红外及光电技术与应用

• Influence of crystal temperature on femtosecond laser induced ferroelectric domain inversion process

  XU Tian-Xiang, WANG Sen, LIN Jin-Yang, ZHAO Ru-Wei, XU Tie-Feng, SHENG Yan

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

  Abstract: (98) HTML (0) PDF (610.75 KKB)(242)

  Abstract:

  The near-infrared femtosecond laser induced ferroelectric domain inversion in an important method in 3D nonlinear photonic crystal fabrication. Using structures produced by this technique， a series of attractive results have been achieved in optical frequency conversion and nonlinear wavefront shaping. At present， the reported laser induced domain inversion were all implemented at room temperature. For ferroelectric crystals， it would reach the Curie point during heating， and many characterizations such as coercive field which relate to domain inversion may change seriously. However， the effect of crystal temperature on femtosecond laser induced domain inversion is undefined. In this work， the strontium barium niobate （Sr_xBa_1-xNbO₃） ferroelectric crystal with the Curie point of about 70-80℃ depends on component proportion of Sr and Ba was used for domain inversion. Direct near-infrared femtosecond laser writing was implemented at the temperature of 25-65℃. The domain inversion condition was judged based on the second-harmonic pattern in the far field. The variation tendency of threshold laser power for domain inversion depends on temperature was tested and possible reason was predicted.

遥感技术与应用

• An adaptive denoising of the photon point cloud based on two-level voxel

  WANG Zhen-Hua, YANG Wu-Zhong, LIU Xiang-Feng, WANG Feng- Xiang, XU Wei-Ming, SHU Rong

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

  Abstract: (71) HTML (46) PDF (3.55 MKB)(257)

  Abstract:

  With a single-photon detector， photon-counting LiDAR （PCL） captures a large amount of background noise along with the target scattered/reflected echo signals， because of the influence of factors such as the background environment， target characteristics， and instrument performance. To accurately extract the signal photons on the ground surface from a noisy photon point cloud （PPC）， this paper presents an adaptive denoising approach for PPC using two levels of voxels. First， coarse denoising is performed utilizing large-scale voxels， which are built based on the spatial distribution features of the PPC. The density of the voxel is then used to select the voxels that contained dense signal photons. Second， fine denoising with small-scale voxels is conducted. These voxels are built using the nearest neighbor distance， and a topologicalrelationship between voxels is used to further extract voxels containing signal photons aggregated on the ground surface. Finally， this method is performed on the PPC from ATL03 datasets collected by the Ice， Cloud， and Land Elevation Satellite-2 both during daytime and at night and compared with the improved Density-Based Spatial Clustering of Applications with Noise （DBSCAN）， improved Ordering Points to Identify the Clustering Structure （OPTICS）， and the method used in the ATL08 datasets. The results show that the proposed method has the best performance， with precision， recall， and F1 score of 0.98， 0.97， and 0.98， respectively.

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红外材料与器件

• Correlation Between the whole small recess offset and Electrical Performance of InP-based HEMTs

  Gong Hang, Zhou Fugui, Feng Ruize, Feng Zhiyu, Liu Tong, Shi Jingyuan, Su Yongbo, Jin Zhi

  DOI:

  Abstract: (96) HTML (0) PDF (1.64 MKB)(183)

  Abstract:

  In this work， we investigate the impact of the whole small recess offset on DC and RF characteristics of InP high electron mobility transistors （HEMTs）. L_g = 80 nm HEMTs are fabricated with a double-recessed gate process. We focus on their DC and RF responses， including the maximum transconductance （g_{m_max}）， ON-resistance （R_ON）， current-gain cutoff frequency （f_T）， and maximum oscillation frequency （f_max）. The devices have almost same R_ON. The g_{m_max} improves as the whole small recess moves toward the source. However， a small gate to source capacitance （C_gs） and a small drain output conductance （g_ds） lead to the largest f_T， although the whole small gate recess moves toward the drain leads to the smaller g_{m_max}. According to the small-signal modeling， the device with the whole small recess toward drain exhibits an excellent RF characteristics， such as f_T = 372 GHz and f_max = 394 GHz. This result is achieved by paying attention to adjust resistive and capacitive parasitics， which play a key role in high-frequency response.

遥感技术与应用

• Serialized orthogonal matching pursuit fusing image domain information for attributed scattering center extraction in SAR images

  LONG Bo, WANG Feng

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

  Abstract: (71) HTML (38) PDF (1.68 MKB)(210)

  Abstract:

  Aiming to address the issue of high complexity in estimating the parameters of the Attribute Scattering Center Model （ASCM） in Synthetic Aperture Radar （SAR） images， a sparse representation parameter estimation method that integrates information from the image domain is proposed. Firstly， the improved watershed algorithm is used to segment the scattering centers of different regions. Subsequently， based on the segmentation results， the frequency domain sparse representation dictionary is decoupled and applied in a serialized manner for scattering center parameter estimation using orthogonal matching pursuit to reduce algorithm complexity. Based on simulated data and measured MSTAR data， the effectiveness and efficiency of the proposed parameter extraction method were validated， and the optimization of theoretical complexity was analyzed. The results indicate that this method can significantly reduce the time and space complexity of the algorithm while achieving results close to those of the conventional orthogonal matching pursuit algorithm. The proposed method can be used for the efficient extraction of scattering center parameters in SAR images.

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红外材料与器件

• DIFNet: SAR RFI suppression network based on domain invariant features

  LV Wen-Hao, FANG Fu-Ping

  DOI:

  Abstract: (89) HTML (0) PDF (1.20 MKB)(181)

  Abstract:

  Synthetic aperture radar (SAR) is a high-resolution two-dimensional imaging radar, however, during the imaging process, SAR is susceptible to intentional and unintentional interference, with radio frequency interference (RFI) being the most common type, leading to a severe degradation in image quality. To address the above problem, numerous algorithms have been proposed. Although inpainting networks have achieved excellent results, their generalization is unclear, and whether they still work effectively in cross-sensor experiments needs further verification. Through time-frequency analysis to interference signals, this work finds that interference holds domain invariant features between different sensors. Therefore, this work reconstructs the loss function and extracts the domain invariant features to improve its generalization. Ultimately, this work proposes a SAR RFI suppression method based on domain invariant features, and embeds the RFI suppression into SAR imaging process. Compared to traditional notch filtering methods, the proposed approach not only removes interference but also effectively preserves strong scattering targets. Compared to PISNet, our method can extract domain invariant features and holds better generalization ability, and even in the cross-sensor experiments, our method can still achieve excellent results. In cross-sensor experiments, training data and testing data come from different radar platforms with different parameters, so cross-sensor experiments can provide evidence for the generalization.

图像处理及软件仿真

• Progressive spatio-temporal feature fusion network for infrared small-dim target detection

  ZENG Dan, WEI Jian-Ming, ZHANG Jun-Jie, CHANG Liang, HUANG Wei

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

  Abstract: (61) HTML (0) PDF (1.67 MKB)(231)

  Abstract:

  To avoid the accumulation of estimation errors from explicitly aligning multi-frame features in current infrared small-dim target detection algorithms， and to alleviate the loss of target features due to network downsampling， a progressive spatio-temporal feature fusion network is proposed. The network utilizes a progressive temporal feature accumulation module to implicitly aggregate multi-frame information and utilizes a multi-scale spatial feature fusion module to enhance the interaction between shallow detail features and deep semantic features. Due to the scarcity of multi-frame infrared dim target datasets， a highly realistic semi-synthetic dataset is constructed. Compared to the mainstream algorithms， the proposed algorithm improves the probability of detection by 4.69% and 4.22% on the proposed dataset and the public dataset， respectively.

红外材料与器件

• High Polarization Extinction Ratio Achieved base on thin-film lithium niobate

  YANG Yong-Kang, GUO Hong-Jie, CHEN Wen-Bin, QU Bai-Ang, YU Zhi-Guo, TAN Man-Qing, GUO Wen-Tao, LIU Hai-Feng

  DOI:

  Abstract: (67) HTML (0) PDF (678.66 KKB)(187)

  Abstract:

  This article introduces a method of achieving high polarization extinction ratio using a subwavelength grating structure on a lithium niobate thin film platform， and the chip is formed on the surface of the lithium niobate thin film. The chip， with a length of just 20 micrometers， achieved a measured polarization extinction ratio of 29dB at 1550nm wavelength. This progress not only proves the possibility of achieving a high extinction ratio on a lithium niobate thin film platform， but also offers important technical references for future work on polarization beam splitters， integrated fiber optic gyroscopes， and beyond.

红外及光电技术与应用

• Research of power improvement of a LD directly-pumped mid-infrared pulse solid-state laser

  ZHANG Meng, YANG Xi, GUO Jia-Wei, CAI He, WU Xin-Yang, HAN Ju-Hong, WANG Shun-Yan, WANG You

  DOI:

  Abstract: (64) HTML (0) PDF (1.60 MKB)(194)

  Abstract:

  A LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle， small size， and compact structure for the generation of mid-infrared （MIR） lasers in the 3~5 μm band. However， the quantum defect of LD directly-pumped MIR solid-state lasers will be much larger than that of ordinary near-infrared LD pumped solid-state lasers， which may lead to thermal damage and limit their development. In order to solve this problem， the methods of reducing the specific surface area of the crystal and improving the thermal energy released by the crystal structure are discussed， and the optimal length of the laser crystal is determined. The cooling structures of barium yttrium fluoride laser crystals （Ho³⁺：BY₂F₈） of different lengths were studied by thermal simulation using COMSOL software. The experimental results show that the output power can be increased and the thermal stress in the laser crystal can be alleviated by using the laser crystal whose length is slightly shorter than that of the cooler. The final experiment shows that when the pump repetition rate is 15 Hz and the pulse width is 90 μs， the single pulse energy is 7.28 mJ at the output wavelength of 3.9 μm， which is about 3 times as large as that of the crystal with the length of 10 mm. Such results should be another breakthrough of our team since the first directly-pumped solid-state MIR laser was realized more than a year ago. It might pave the way for the construction of a feasible MIR laser in the near future.

太赫兹与毫米波技术

• 75-110 GHz wideband Frequency Tripler Chip Based on Planar Schottky Diode

  CHEN Yan, MENG Fan-Zhong, XUE Hao-Dong, ZHANG Ao, GAO Jianjun

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

  Abstract: (43) HTML (0) PDF (1.47 MKB)(194)

  Abstract:

  Based on GaAs planar Schottky diode process， a W band wideband frequency tripler MMIC is designed with a reverse parallel diode pair in this paper. By combining of finite element method and equivalent circuit method， an accurate equivalent circuit model of the planar Schottky diode is built in the frequency range of 10~280GHz. The nonlinear harmonic balance tool is utilized to achieve the optimal frequency tripler design in W band. The measurement results show that the frequency multiplication loss is less than 15dB under 17dBm driving power， efficiency up to 6.7%. The chip size is 0.80mm×0.65mm×0.05mm．

图像处理及软件仿真

• Deep Plug-and-Play Self-Supervised Neural Networks for Spectral Snapshot Compressive Imaging

  Zhang Xing-Yu, Zhu Shou-Zheng, Zhou Tian-Shu, Qi Hong-Xing, Wang Jian-Yu, Li Chun-Lai, Liu Shi-Jie

  DOI:

  Abstract: (100) HTML (0) PDF (1.07 MKB)(216)

  Abstract:

  The coded aperture snapshot spectral imaging system， based on compressed sensing theory， functions as an capable of efficiently acquiring compressed two-dimensional spectral data. This data is subsequently decoded into three-dimensional spectral data through a deep neural network. However， training the deep neural network necessitates a substantial amount of clean data， which is often challenging to obtain. To address the issue of insufficient training data for deep neural network， a self-supervised hyperspectral denoising neural network is proposed， leveraging the concept of neighborhood sampling. This network is integrated into the deep plug-and-play framework， enabling self-supervised spectral reconstruction. The study also examines the impact of different noise degradation models on the final reconstruction quality. Experimental results demonstrate that compared with supervised learning method， the self-supervised learning method enhances the average peak signal-to-noise ratio by 1.18dB and improves the structural similarity is improved by 0.009. Additionally， it achieves superior visual reconstruction outcomes without relying on clean data as labels.

红外光谱与光谱分析

• Study on Multi-wavelength Thin Film Thickness Determination Method

  SHI Ce, XIE Mao-Bin, ZHENG Wei-Bo, JI Ruo-Nan, WANG Shao-Wei, LU Wei

  DOI:

  Abstract: (56) HTML (0) PDF (839.04 KKB)(162)

  Abstract:

  This work introduces a novel method for measuring thin film thickness， employing a multi-wavelength method that significantly reduces the need for broad-spectrum data. Unlike traditional techniques that require several hundred spectral data points， the multi-wavelength method achieves precise thickness measurements with data from only 10 wavelengths. This innovation not only simplifies the process of spectral measurement analysis but also enables accurate real-time thickness measurement on industrial coating production lines. The method effectively reconstructs and fits the visible spectrum （400-800 nm） using a minimal amount of data， while maintaining measurement error within 7.1%. This advancement lays the foundation for more practical and efficient thin film thickness determination techniques in various industrial applications.

红外材料与器件

• Enhancement of mid-wavelength infrared absorbance by alkane-grafted Ti₃C₂T_x MXene thin-films

  Zhao Zhenyu, Hideaki Kitahara, Zhang Chenhao, Masahiko Tani

  DOI:

  Abstract: (34) HTML (0) PDF (868.83 KKB)(125)

  Abstract:

  An enhancement of mid-wavelength infrared absorbance is achieved via a cost-effectively chemical method to bend the flakes by grafting two types of alkane octane （C₈H₁₈） and dodecane （C₁₂H₂₆） onto the surface terminals respectively. The chain-length of alkane exceeds the bond-length of surface functionalities Tx （=O，-OH，-F） so as to introduce intra-flake and inter-flake strains into Ti₃C₂T_x MXene. The electronic microscopy （TEM/AFM） shows obvious edge-fold and tensile/compressive deformation of flake. The alkane termination increases the intrinsic absorbance of Ti₃C₂T_x MXene from no more than 50% down to more than 99% in the mid-wavelength infrared region from 2.5 μm to 4.5 μm. Such an absorption enhancement attribute to the reduce of infrared reflectance of Ti₃C₂T_x MXene. The C-H bond skeleton vibration covers the aforementioned region and partially reduce the surface reflectance. Meanwhile， the flake deformation owing to edge-fold and tensile/compression increase the specific surface area so as to increase the absorption as well. These results have applicable value in the area of mid-infrared camouflage.

• Research on error analysis and instrument parameter configuration of emissivity measurement of multispectral radiometric method based on slow-change assumption

  Luan Yi-Fei, Wang Xiang, Gu Luo, Lin Yue, Yang Qiu-Jie, He Zhi-Ping

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

  Abstract: (60) HTML (0) PDF (1.39 MKB)(181)

  Abstract:

  Emissivity， as a key parameter to characterize the radiation properties of an object， and its accurate measurement is of great value for high-temperature target identification， characterization of material modification， and regulation of metal smelting process. The emissivity measurement by multispectral radiation method has become a research hotspot because of its advantages of non-contact and fast measurement speed， and its measurement accuracy is determined by the solution accuracy of the underdetermined system of equations. At present， the research on the solution accuracy of the underdetermined system of equations mainly focuses on the error of the equation solving algorithm， ignoring the measurement error of the spectrometer itself， which leads to the failure of controlling the system error in a reasonable way. In this paper， based on the assumption of retardation with wide application range and high measurement accuracy， the influence of the number of spectral channels and signal-to-noise ratio on the emissivity measurement error under different conditions is simulated， the parameter configurations of the spectrometer under the corresponding conditions are determined， and the effect of emissivity measurement is experimentally verified. The experimental results show that， using the multispectral radiation method based on the slow-change assumption， the number of spectral channels of the spectrometer should be not less than 400 and the signal-to-noise ratio should not be less than 1000 in order to make the blackbody emissivity measurement error less than 1%； for the targets with complex emissivity changes， the spectrometer should have at least 1，000 spectral channels and signal-to-noise ratios of more than 1，200 in order to make the measurement error less than 1%. Comprehensive consideration of the algorithm error and spectrometer parameter matching relationship is the key to rationally control the system error， and more accurate emissivity measurement results can be obtained， which provides a new basis and solution for the application of multispectral radiation method to accurately measure the emissivity， which is of great significance for the accurate identification of high-temperature targets and the application of the related fields.

红外及光电技术与应用

• Angular-tunable on-chip coding metasurface enabled by phase-change material with immersion liquid

  LI Xue-Nan, ZHAO Zeng-Yue, YU Fei-Long, CHEN Jin, LI Guan-Hai, LI Zhi-Feng, CHEN Xiao-Shuang

  DOI:

  Abstract: (97) HTML (0) PDF (1.42 MKB)(155)

  Abstract:

  Metasurfaces provide a potent platform for the dynamic manipulation of electromagnetic waves. Coupled with phase-change materials， they facilitate the creation of versatile metadevices， showcasing various tunable functions based on the transition between amorphous and crystalline states. However， the inherent limitation in tunable states imposes constraints on the multiplexing channels of metadevices. Here， this paper introduce a novel approach—a multi-functional metadevice achieved through the two-level control of the encoding phase-change metaatoms. Utilizing the phase-change material Ge₂Sb₂Se₄Te₁ （GSST） and high refractive-index liquid diiodomethane （CH₂I₂）， this paper showcase precise control over electromagnetic wave manipulation. The GSST state governs the tunable function， switching it ON and OFF， while the presence of liquid in the hole dictates the deflection angle when the tunable function is active. Importantly， our tunable coding metasurface exhibits robust performance across a broad wavelength spectrum. The incorporation of high refractive-index liquid extends the regulatory dimension of the metadevice， enabling dynamic switching of encoding bit levels. This two-level tunable metadevice， rooted in phase-change materials， presents a promising avenue for the dynamic control of functions.

红外材料与器件

• Study on photoelectric performance of ultra-small pixel pitch micro-mesa InGaAs detector

  TIAN Yu, YU Chun-Lei, LI Xue, SHAO Xiu-Mei, LI Tao, YANG Bo, YU Xiao-Yuan, CAO Jia-Shen, GONG Hai-Mei

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

  Abstract: (57) HTML (0) PDF (2.14 MKB)(194)

  Abstract:

  The pursuit of ultra-small pixel pitch InGaAs detectors necessitates a meticulous approach to addressing challenges associated with crosstalk reduction and dark current minimization. By developing the fabrication process technology of micro-mesa InGaAs detector， a test structure featuring a micro-mesa InGaAs photosensitive chip with 10μm and 5μm pixel pitch was successfully prepared. Subsequently， a comprehensive investigation was conducted to analyze the impact of the micro-mesa structure on crosstalk and dark current characteristics of the InGaAs detector. The obtained results revealed the efficacy of the micro-mesa structure in effectively suppressing crosstalk between adjacent pixels when the isolation trench etches into the absorption layer. However， a noteworthy challenge emerged as the fabrication processes induced material damage， leading to a considerable increase in recombination current and ohmic leakage current. This adverse effect， in turn， manifested as a dark current escalation by more than one order of magnitude. The significance of these findings lies in offering a novel perspective for the manufacturing of ultra-small pixel pitch InGaAs focal plane detectors.

• Ion Implantation Process and Lattice Damage Mechanism of Boron Doped Crystalline Germanium

  HABIBA Um E, Chen Tianye, Liu Chixian, Dou Wei, Liu Xiaoyan, Ling Jingwei, Pan Changyi, Wang Peng, Deng Huiyong, Shen Hong, Dai Ning

  DOI:

  Abstract: (262) HTML (54) PDF (1.05 MKB)(162)

  Abstract:

  The response wavelength of the blocked-impurity-band (BIB) structured infrared detector can reach 200μm, which is the most important very long wavelength infrared astronomical detector. The ion implantation method greatly simplifies the fabrication process of the device, but it is easy to cause lattice damage, introduce crystalline defects, and lead to the increase of the dark current of detectors. Herein, the boron-doped germanium ion implantation process was studied, and the involved lattice damage mechanism was discussed. Experimental conditions involved using 80 keV energy for boron ion implantation, with doses ranging from 1×1013 to 3×1015cm-2. After implantation, thermal annealing at 450°C was implemented to optimize dopant activation and mitigate the effects of ion implantation. Various sophisticated characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS) were used to clarify lattice damage. At lower doses, no notable structural alterations were observed. However, as the dosage increased, specific micro distortions became apparent, which could be attributed to point defects and residual strain. The created lattice damage was recovered by thermal treatment, however, an irreversible strain induced by implantation still existed at the high doses

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• Investigation of Polarization Characteristics in Semiconductor Master Oscillator Power Amplifier

  WANG Hao-Miao, HE Yu-Wen, LI Yi, HU Yao, ZHANG Liang, DU Wei-Chuan, GAO Song-Xin, TANG Chun, MA Xiao-Yu, LIU Su-Ping

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

  Abstract: (108) HTML (0) PDF (1.04 MKB)(379)

  Abstract:

  To improve of polarization of master oscillator power amplifier （MOPA）， the factors which have impact on the polarization characteristics of ridge and tapered waveguides are studied. The optical confinement factor of TE-mode in ridge waveguide is enlarged by 1.35 μm deep etching， whereas the TE optical gain in tapered amplifier is improved through on-chip metal stress regulation. Combining the methods above， the degree of polarization （DOP） of two section are prominently enhanced in addition to reduced polarization angle difference. Finally， a 90% DOP of the MOPA has been achieved by standard process fabrication.

• 12.5μm 1024×1024 long-wavelength infrared InAs/GaSb Type II superlattice focal plane arrays

  BAI Zhi-Zhong, HUANG Ming, Xu Zhi-Cheng, ZHOU Yi, ZHU Yi Hong, SHEN Yi-Ming, ZHANG Jun-Lin, CHEN Hong-Lei, DING Rui-Jun, CHEN Jian-Xin

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

  Abstract: (137) HTML (0) PDF (972.07 KKB)(291)

  Abstract:

  In this paper， we report research results of 12.5μm long-wavelength infrared InAs/GaSb superlattice focal plane arrays. The superlattice structure was grown on GaSb substrate using molecular beam epitaxy （ MBE） technology. The respective structure of absorption region is 15ML （ InAs） /7ML （ GaSb）. The detector adopts PBπBN double barrier structure to suppress the dark current. A long-wave focal plane detector with the size of 1024×1024 and the pixel center-to-center distance of 18×18μm was developed. The detector is packaged by a metal dewar， and a superlattice long-wavelength detector cryocooler assembly is formed by coupling with a refrigerator. At 60 K measurement， the detector has 50% cut-off wavelength of 12.5μm， The detector has a peak detectivity of 6.6×10¹⁰cmHz^1/2W^-1 ， dead pixels rate of 1.05% and a noise equivalent temperature difference （NETD） is 21.2mK. Infrared images of this detector has been taken using infrared imaging test.

• Extracting the effective mass of fewer layers 2D h-BN nanosheets using the Fowler Nordheim tunneling model

  Qin Jia-Yi, Luo Man, Cheng Tian-Tian, Meng Yu-Xin, Zu Yuan-Ze, Wang Xin, Yu Chen-Hui

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

  Abstract: (191) HTML (0) PDF (873.33 KKB)(334)

  Abstract:

  Hexagonal boron nitride (h-BN) finds widespread application, including gate dielectrics, passivation layers, and tunneling layers, owing to its outstanding properties. The current studies on the fundamental physical properties of these ultrathin h-BN films and the electron tunneling effect among them are inadequate. In this work, the effective mass in h-BN was successfully determined through a combined approach of experimental and theoretical research methods by fitting the current-voltage curves of metal/insulator/metal structures. It was observed that within a range of 4~22 layers, the effective mass of h-BN exhibits a monotonic decrease with an increase in the number of layers. Precisely ascertain the physical parameters of the Fowler-Nordheim tunneling model in the context of electron tunneling in h-BN by utilizing the extracted effective mass. Additionally, the impact of fixed charges at the metal/h-BN interface and various metal electrode types on Fowler-Nordheim tunneling within this structure was investigated utilizing this physical parameter in Sentaurus TCAD software. This work is informative and instructive in promoting applications in the fields of h-BN related infrared physics and technology.

• A High Output Power 340GHz Balanced Frequency Doubler Design Based on Linear Optimization Method

  Zhicheng Liu, Jingtao Zhou, Jin Meng, Haomiao Wei, Chengyue Yang, Yongbo Su, Zhi Jin, Rui Jia

  Abstract: (8) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In this paper, a linear optimization method(LOM) for the design of terahertz circuits is presented, aimed at enhancing simulation efficacy and reducing the time of the circuit design workflow. This method enables the rapid determination of optimal embedding impedance for diodes across a specific bandwidth to achieve maximum efficiency through harmonic balance simulations. By optimizing the linear matching circuit with the optimal embedding impedance, the method effectively segregates the simulation of the linear segments from the nonlinear segments in the frequency multiplier circuit, substantially increasing the speed of simulations. The design of on-chip linear matching circuits adopts a modular circuit design strategy, incorporating fixed load resistors to simplify the matching challenge. Utilizing this approach, a 340GHz frequency doubler was developed and measured. The results demonstrate that, across a bandwidth of 330GHz to 342GHz, the efficiency of the doubler remains above 10%, with an input power ranging from 98mW to 141mW and an output power exceeding 13mW. Notably, at an input power of 141mW, a peak output power of 21.8mW was achieved at 334GHz, corresponding to an efficiency of 15.8%.

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• BDMFuse: Multi-Scale Network Fusion for Infrared and Visible Images Based on base and Detail Features

  Si Hai-ping, Zhao Wen-rui, Li Ting-ting, Li Fei-tao, Feiernanduo.Basang, Sun Chang-xia, Li Yan-ling

  Abstract: (21) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The result of infrared and visible image fusion should highlight the significant targets of the infrared image while preserving the visible light texture details. In order to satisfy the above requirements, this paper proposes an automated encoder-based infrared and visible image fusion method. The encoder constructs both a base encoder and a detail encoder according to the optimization objective. The base encoder extracts low-frequency information from the image, while the detail encoder captures high-frequency information. Since this extraction method may miss some information, we introduce a compensation encoder to supplement the missing information. Additionally, we introduce multi-scale decomposition for the encoder to extract image features more comprehensively. The image features obtained by the encoders are then fed into the decoder. The decoder first adds the low-frequency, high-frequency and compensatory information to obtain multi-scale features. An attention map is derived from these multi-scale features and multiplied with the fused image at the corresponding scale. The Fusion module is introduced in the multi-scale fusion process to achieve image reconstruction. The network proposed in this paper demonstrates its effectiveness on the TNO, RoadScene, and LLVIP datasets. Experiments show that our network can better perceive changes in light, effectively extract image detail information, and produce fused images that are more aligned with human visual perception.

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• Urban Tree Species Classification with Multispectral Airborne LiDAR

  Peilun Hu, Yuwei Chen, Mohammad Imangholiloo, Markus Holopainen, Yicheng Wang, Juha Hyyppä

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

  Abstract:

  Urban tree species provide various essential ecosystem services in cities, such as mediating urban temperature, isolating noise, fixing carbon, and alleviating the urban heat island effect. The quality of these services is influenced by species diversity, tree growth status, and the distribution and composition of trees. Traditionally, data about urban trees has been gathered through field data collection and manual interpretation of remote sensing images. In this study, we evaluate the capacity of using Multispectral Airborne Laser Scanning (ALS) data to classify 24 common urban roadside tree species in Espoo, Finland. We utilized tree crown structure information, intensity features, and spectral information for classification. The results demonstrated an overall accuracy of 71.5% using multispectral LiDAR data, highlighting that combining structural and spectral information in a single frame could enhance classification accuracy. In the future, we will focus on identifying the most important features in species classification and finding algorithms with higher efficiency and accuracy.

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• Tidal flats extraction in the coastal zone based on time-series Sentinel-2 imagery and near-infrared tidal flats indices

  zhourujia, XIA Qing, ZHENG Qiong, ZHU Li-Hong, LI Bin, Li Jianhua, SONG Jia

  Abstract: (29) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  When extracting coastal zone tidal flats using remote sensing transient images, the influence of tides greatly limits the accuracy of tidal flat spatial distribution extraction. In this paper, based on the Google Earth Engine (GEE) cloud platform, a coastal zone tidal flats extraction method by combining the time-series Sentinel-2 image and the tidal flats index is proposed. First, based on the Sentinel-2 time-series image data, we use the quantile synthesis method to generate high- and low-tide images, and then analyze the spectral reflectance characteristics of different land classes on the high- and low-tide images. A NIR-band tidal flat extraction index that excludes the interference of the tidal transient is constructed. Secondly, the image spectral information and the tidal flat extraction index are input into a machine learning algorithm to realize fast and efficient extraction of the tidal flat. Finally, the separability of the tidal flats index and the universality are investigated. The results show that the tidal flats extraction index constructed in this research had a good separability for tidal flats, the overall accuracy of tidal flats extraction was 93.02%, the Kappa coefficient was 0.86, and the proposed method has good applicability to remote sensing images containing near-infrared bands. This method can realize automatic and rapid tidal flat extraction, and provide data support for the sustainable management and protection of coastal zone resources.

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• Detection and quantification of water / ice in typical lunar minerals using Raman spectroscopy

  WEN Dao-Yuan-Tian, Zhao Hai-Ting, LIU Xiang-Feng, XU Wei-Ming, XU Xue-Sen, LEI Xin-Rui, SHU Rong

  Abstract: (32) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The water in lunar materials can promote the evolution of lunar geology and environment and provide the necessary conditions for the utilization of lunar resource. Owing to the low resolution of lunar remote sensing methods, it is difficult to obtain direct evidence of water / ice or determine its form of occurrence. Laser Raman spectroscopy can obtain fingerprint information of minerals and water bodies without the need for illumination, sample pretreatment, and non-destructive, providing direct and favorable information regarding the type, distribution range, and content of lunar materials. In this study, Raman spectroscopy was used to detect the water-containing characteristics of typical lunar rocks/minerals and forms such as adsorbed water, ice, crystalline water, and hydroxyl-structured water, and quantitatively analyze the water content. First, a 532 nm laser micro-Raman spectroscopy was used to identify and analyze the water-containing signals of typical lunar minerals and various forms of water in lunar soil simulants. Second, the detection limits of adsorbed water, crystalline water, and hydroxyl-structured water in lunar soil simulants were examined and analyzed, along with the patterns between their content and signal intensity. Finaly, linear regression (LR), ridge regression (RR), and partial least squares regression (PLSR) were employed for quantitatively analyze of the contents of three forms of water in the lunar soil simulants. The results show that (1) the characteristic spectral peaks of the four forms of water in the lunar soil simulants can be clearly identified. The peak distribution regions of the lunar soil simulants components and water bodies are located at 100-1700 cm-1 and 2600-3900 cm-1, respectively. The characteristic spectral peaks of water are manifested as a combination of broad envelope peaks of hydrogen-bonded OH and sharp peaks of non-hydrogen-bonded OH stretching vibrations in varying proportions. (2) Detection limits of adsorbed water, crystalline water (MgSO4·7H2O), and hydroxyl water (Al2Si2O5(OH)4) in the lunar soil simulants are 1.3 wt%, 0.8 wt%, and 0.3 wt%, respectively. (3) A linear relationship exists between the intensity of water-containing peaks and the water content in the lunar soil simulants, with root mean square errors of 1.75 wt%, 1.16 wt%, and 1.19 wt% obtained through LR, RR, and PLSR.

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• Simulation design of short-wave infrared heterogeneous phototransistor for weak light detection

  LIAO Ke-Cai, HUANG Min, WANG Nan, LIANG Zhao-Ming, ZHOU Yi, CHEN Jian-Xin

  Abstract: (26) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The sensitivity of the detector is the core technical indicator of the infrared detector. Short-wave infrared detector has low dark current and the sensitivity will be limited by the inherent read-out circuit noise of the detection system. Therefore, it is an effective way to further enhance the sensitivity by introducing internal gain into the detector. Heterogeneous phototransistor takes advantages of high gain, low operating bias, and low excess noise, which provides novel approach for high-sensitive detection. This paper mainly focuses on the simulation design of InGaAs/GaAsSb type-II superlattice short-wave infrared phototransistor, and studies the dependence of the device size on the optoelectronic characteristics. The results show that a higher gain, a lower dark current, and a faster response can be achieved by a smaller base size. Based on the optimization design of size structure, a sensitivity with a noise equivalent photon lower than 10 can be achieved, which provides a new technical approach to achieve high-sensitive heterogeneous phototransistor detector.

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• Infrared small target detection method based on nonconvex tensor Tuck decomposition with factor prior

  yangjungang, 刘婷, liuyongxian, liboyang, wangyingqian, shengweidong, anwei

  Abstract: (45) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Low-rank and sparse decomposition method (LRSD) has been widely concerned in the field of infrared small target detection because of its good detection performance. However, existing LRSD-based methods still face the problems of low detection performance and slow detection speed in complex scenes. Although existing low-rank Tuck decomposition methods achieve satisfactory detection performance in complex scenes, they need to define ranks in advance according to experience, and too large or too small the estimated ranks will lead to missed detection or false alarms. Meanwhile, the size of rank is different in different scenes. This means that they are not suitable for real-world scenes. To solve this problem, this paper uses non-convex rank approach norm to constrain latent factors of low-rank Tucker decomposition, which avoids setting ranks in advance according to experience and improves the robustness of the algorithm in different scenes. Meanwhile, an symmetric GaussSeidel (sGS) based alternating direction method of multipliers algorithm (sGSADMM) is designed to solve the proposed method. Different from ADMM, the sGSADMM algorithm can use more structural information to obtain higher accuracy. Extensive experiment results show that the proposed method is superior to other advanced algorithms in detection performance and background suppression.

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Volume 43,2024 Issue 4

• SEGMENTATION BASED ON MUMFORD-SHAH MODEL COMBINED WITH NARROW BAND

  Abstract

  2002,21(3):161-166, DOI:

  Abstract: (2385) HTML (123) PDF (392.26 KKB)(82677)

  Abstract:

  A segmentation model that combines the Mumford Shah(M S) model and narrow band scheme of level set was presented. The disadvantage of Mumford Shah model is computationally time consuming. In each step of its iteration, the data of whole image have to be renewed, which is unbearable for segmentation of large image or 3D image. Therefore, a fast segmentation model was introduce, which combines the M S model and narrow band scheme by a new initialization method. The new initialization method is based on fast marching method, and the computing time decreases to O(N) . In each step of iteration, the new segmentation model only deals with the data in a narrow band instead of the whole image. The experiments show that the two models can obtain almost the same segmentation result, but the computing time of new narrow band M S model is much less than that of M S model.

• 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: (1631) HTML (139) PDF (262.82 KKB)(52507)

  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。

• TWO-FREQUENCY SCATTERING CROSS SECTION AND PULSE BROADINGENING FOR THE FRACTAL SEA SURFACE WITH PULSE BEAM INCIDENCE

  GUO Li Xin 1) KIM Che Young 2)

  2003,22(2):132-136, DOI:

  Abstract: (963) HTML (132) PDF (396.69 KKB)(51087)

  Abstract:

  根据粗糙面基尔霍夫小斜率近似研究了脉冲波入射时实际海谱分布的一维分形海面的电磁散射。分析了毫米波入射时不同分维、入射角和入射中心频率下双频散射截面的散射角分布。结果表明分形海面的双频散射截面在镜反射方向有最大的相关带宽，随着海面分维的减小、入射中心频率和入射角的增加，该相关带宽是增大的。对于入射功率为δ函数时的散射波功率是一个具有一定脉冲展宽的散射脉冲，且脉冲展宽与相关带宽成反比关系。

• 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: (7710) HTML (465) PDF (411.06 KKB)(21735)

  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。

• OPTICAL SPECTRA OF LOW-DIMENSIONAL SEMICONDUCTORS

  FuY ChiragwandiZ GoethbergP WillanderM

  2003,22(6):401-405, DOI:

  Abstract: (971) HTML (128) PDF (483.11 KKB)(21476)

  Abstract:

  We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.

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: (10553) HTML (415) PDF (221.64 KKB)(15561)

  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: (7325) HTML (402) PDF (271.63 KKB)(14878)

  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.

• A NOVEL NEURAL NETWORK LEARNING METHOD OF DYNAMICALLY TUNING REGULARIZATION COEFFICIENT ACCORDINT TO FUZZY RULES

  WU Yan 1), 2) ZHANG Li Ming 2)

  2002,21(3):189-194, DOI:

  Abstract: (1400) HTML (94) PDF (450.58 KKB)(13432)

  Abstract:

  Based on bias variance model, a novel method of dynamically tuning the regularization coefficient by fuzzy rules inference was proposed. The fuzzy inference rules and membership functions were effectively determined. Furthermore, the method was compared with the traditional BP algorithm and fixed regularization coefficien's method. The result is that the proposed method has the merits of the highest precision, rapid convergence and best generalization capacity. The capacity proposed method is shown to be a very effective method by several examples simulation.

Image Processing and Software Simulation

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

  ZHOU Yue, MAO Xiao-Nan

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

  Abstract: (11366) HTML (439) PDF (750.21 KKB)(12533)

  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.

• HYPERSPECTRAL REMOTE SENSING IMAGE CLASSIFICATION BASED ON SUPPORT VECTOR MACHINE

  TAN Kun, DU Pei-Jun

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

  Abstract: (2945) HTML (936) PDF (735.00 KKB)(12441)

  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 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: (11374) HTML (387) PDF (808.83 KKB)(12371)

  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.

• IMAGE FUSION SCHEME OF PIXEL-LEVEL AND MULTI-OPERATOR FOR INFRARED AND VISIBLE LIGHT IMAGES

  LIU Gui Xi YANG Wan Hai

  2001,20(3):207-210, DOI:

  Abstract: (1246) HTML (111) PDF (196.71 KKB)(12155)

  Abstract:

  A novel pixel level image fusion scheme was presented based on multiscale decompositon. First, the wavelet transform is used to perform a multiscale decomposition of each image. Then, the wavelet coefficients of fused image are constructed using multiple operators according to different fusion rules. This approach is successfully used to fuse the infrared and visible light images. The experimental results show that the fusion scheme is effective and the fused images are more suitable for human visual or machine perception.

Remote Sensing Technology and Application

• A method for fire detection using Landsat 8 data

  HE Yang, YANG Jin, MA Yong, LIU Jian-Bo, CHEN Fu, LI Xin-Peng, YANG Yi-Fei

  2016,35(5):600-609, DOI: 10.11972/j.issn.1001-9014.2016.05.015

  Abstract: (3658) HTML (239) PDF (5.05 MKB)(11713)

  Abstract:

  Traditional fire detection methods use the high temperature emission characteristics in mid or thermal infrared bands of the MODIS or AVHRR data to extract burning area. It is very hard for these methods to identify small fire regions such as sub-pixel due to the limitation of spatial resolution. Recently researchers have found that shortwave infrared (SWIR) data can also be used to identify and detect high temperature targets. Compared with the thermal infrared data, SWIR has a big discrimination against different features with different temperature. Thus it can identify accurately the location of high temperature targets. In this paper, we acquired fire point products by using Landsat-8 OLI data which has spatial resolution up to 30 m. The main procedure includes two steps. The improved Normalized Burning Ratio Short-wave(NBRS) is calculated at first to adaptively acquire suspected fire points based on the spectral characteristics of fire points in the near infrared and shortwave infrared. Then most false positive points are excluded based on the relationship between peak value in shortwave infrared band of fire points. This algorithm is capable of detecting the burning area around 10% in one pixel. With the premise of avoiding the interference of cloud and constructions, it can also keep a nearly 90% accuracy and low missing rate around 10%.

Infrared Materials and Devices

• Graphene oxide: progress in preparation, reduction and application

  ZHANG Qian, TANG Li-Bin, LI Ru-Jie, XIANG Jin-Zhong, HUANG Qiang, LIU Shu-Ping

  2019,38(1):79-90, DOI: 10.11972/j.issn.1001-9014.2019.01.014

  Abstract: (3120) HTML (215) PDF (4.42 MKB)(11591)

  Abstract:

  With the rapid development of graphene industry, graphene oxide has attracted much attention as an important intermediate product for the preparation of graphene. Due to its excellent physical and chemical properties, it has been widely used in multitudinous fields. Various structural models, preparation methods, properties and related applications, as well as the reduction of graphene oxide are summarized. The choice of oxidants and reduction agents were found to be important in the reaction. The basic selective principles are discussed after comparing various methods. Finally, it is pointed out that there are still some problems to be solved in the preparation and reduction of graphene oxide. The prospect of graphene oxide on its development and influence will also be evaluated.

• 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: (1396) HTML (99) PDF (380.01 KKB)(11466)

  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.

• 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: (11757) HTML (435) PDF (1.12 MKB)(11440)

  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.

• METHOD OF SCATTERING CENTER ESTIMATION BY RADAR TARGET FREQUENCY RESPONSE DATA IN CLUTTER ENVIRONMENT

  JIANG Wei Dong CHEN Zen Ping ZHUANG Zhao Wen GUO Gui Rong

  2001,20(2):111-116, DOI:

  Abstract: (876) HTML (103) PDF (331.55 KKB)(10939)

  Abstract:

  The simulation methods of radar clutter with given amplitude distribution and power spectrum were described, and the simulation results of radar clutter were given. A scattering center model of frequency domain of radar target was presented under the clutter environment and its solution method was studied. Finally, the experimental results of simulation data and the measurement data of aircraft scale model were given.

• 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: (7837) HTML (181) PDF (466.11 KKB)(10015)

  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: (2662) HTML (131) PDF (1.09 MKB)(9946)

  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.

• STUDY ON PERCEPTUAL EVALUATION OF FUSED IMAGE QUALITY FOR COLOR NIGHT VISION

  SHI Jun-Sheng 1, 2, JIN Wei-Qi 1, WANG Ling-Xue 1

  2005,24(3):236-240, DOI:

  Abstract: (1257) HTML (120) PDF (334.87 KKB)(9730)

  Abstract:

  With the development and the application of visible-IR image fusion techniques in color vision night, evaluating the performance of image-fused algorithms is becoming an important aspect. In this study, three basic visual evaluation factors, target detection, details and colorfulness, were presented for evaluating perceptual quality of color fused images, and the degree of correlation between the perceptual quality and the three evaluation factors was investigated. Visual evaluation experiment on the color images fused visible and IR images of ten scenes by four fusion algorithms was conducted. The experimental results show that the fuesd images have good performances in target detection, the correlation coefficient between the perceptual qulity and details is 0.89, and the correlation coefficient between the perceptual qulity and colorfulness is 0.75 . It indicates that details are the main factor and the colorfulness plays an important role when targets are beyong the detected level.