Volume 44,2025 Issue 2

Infrared Physics, Materials and Devices

• 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

  2025,44(2):144-152 ,DOI: 10.11972/j.issn.1001-9014.2025.02.001

  Abstract: (6) HTML (2) PDF (2.65 MKB)(6)

  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 detection 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 detection sensitivity by introducing internal gain into the detector. The heterogeneous phototransistor has advantages of high gain， low operating bias， and low excess noise， which provides a 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 and structure 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-area size. Based on the optimization design of the device size and structure， a noise equivalent photon lower than 10 can be achieved， which provides a new technical approach to achieve high-sensitive heterogeneous phototransistor detector.

• Study on the preparation and spectroscopic ellipsometry of MoTe₂ quantum dot films

  LI Guo-Bin, HU Kun, ZHANG Tai-Wei, YANG Ao, XIA Yi-Ping, LI Xue-Ming, TANG Li-Bin, YANG Pei-Zhi, WANG Shan-Li, CHEN Sheng-Di, YANG Li, ZHANG Yan

  2025,44(2):153-160 ,DOI: 10.11972/j.issn.1001-9014.2025.02.002

  Abstract: (3) HTML (6) PDF (4.53 MKB)(5)

  Abstract:

  The preparation of quantum dot thin films and the accurate measurement of optical constants are particularly important for promoting the development of quantum dot applications in the optoelectronic fields. At present， the optical constant characterization technology for MoTe₂ single crystal thin films prepared by mechanical exfoliation and chemical vapor deposition methods is relatively mature. However， the optical constants of 2H-MoTe₂ quantum dot films are rarely reported.In this work， 2H-MoTe₂ quantum dots were prepared by ultrasonic assisted liquid phase exfoliation， and 2H-MoTe₂ quantum dots with two sizes were acquired via adjusting the type of solvent and the order of ultrasonic process. The optical constants such as refractive index， extinction coefficient and dielectric constant of quantum dot films with two sizes were studied by B-spline model and Tauc-Lorentz model using spectroscopic ellipsometry. The results demonstrate that 2H-MoTe₂ quantum dots with two sizes have similar refractive indices， extinction coefficients and a wider spectral absorption range from the visible to near-infrared band. And compared with MoTe₂ bulk material， 2H-MoTe₂ quantum dots have a lower dielectric constant.

• Time and frequency domain characteristics control 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

  2025,44(2):161-167 ,DOI: 10.11972/j.issn.1001-9014.2025.02.003

  Abstract: (4) HTML (1) PDF (1.20 MKB)(18)

  Abstract:

  Lasers with wavelengths around 2 μm are located in the atmospheric transmission window and at the strong absorption peak of water， and have important applications in medicine， light detection and ranging（LIDAR）， material processing， and 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 a 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 1 939.2 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 waveform and spectral characteristics.

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Millimeter Waves and Terahertz Technology

• Design of a wideband non-uniform microstrip line for complex impedance matching in automotive radar frequencies

  ZHANG Shuang-Gen, YU Tao, WANG Yu-Lan, CHENG Zhi-Hua, YAO Jian-Quan

  2025,44(2):168-176 ,DOI: 10.11972/j.issn.1001-9014.2025.02.004

  Abstract: (2) HTML (1) PDF (2.59 MKB)(6)

  Abstract:

  Microstrip transmission lines connecting to the millimeter wave radar chip and antenna significantly affect the radiation efficiency and bandwidth of the antenna. Here， a wideband non-uniform wavy microstrip line for complex impedance in automotive radar frequency range is proposed. Unlike the gradient transmission line， the wavy structure is composed of periodically semi-circular segments. By adjusting the radius of the semi-circular， the surface current is varied and concentrated on the semi-circular segments， allowing a wider tunability range of the resonant frequency. The results reveal that the bandwidth of the loaded wavy transmission line antenna improves to 9.37 GHz， which is 5.81 GHz wider than that of the loaded gradient line. The gain and the half power beam width of the loaded antenna are about 14.69 dB and 9.58°， respectively. The proposed non-uniform microstrip line scheme may open up a route for realizing wideband millimeter-wave automotive radar applications.

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• The research on polarization-tunable terahertz GaAs photoconductive antenna array

  DONG Chen-Gang, SHI Wei, HAN Xiao-Wei, WANG Zhi-Quan, WANG Xin, ZHANG Xiu-Xing

  2025,44(2):177-183 ,DOI: 10.11972/j.issn.1001-9014.2025.02.005

  Abstract: (1) HTML (1) PDF (1.14 MKB)(2)

  Abstract:

  As an important emitter for terahertz radiation， photoconductive antenna arrays are limited in their application flexibility due to the fixed polarization state of traditional antennas. In response to this issue， we have designed and studied a polarization-adjustable four-element terahertz gallium arsenide photoconductive antenna array， aiming to enhance its versatility and applicability in various applications. By precisely controlling the excitation of each element， the antenna array can achieve precise control of linearly and circularly polarized terahertz waves through in-phase unequal amplitude excitation and phase difference excitation. The results show that with in-phase unequal amplitude excitation， flexible control of linearly polarized terahertz waves within a 360-degree range can be achieved. With a 90-degree phase difference excitation， circularly polarized terahertz waves are generated， with a -10 dB impedance bandwidth range of 0.057-1.013 THz and a relative bandwidth of 178.69%. The axial ratio bandwidth range is 0.815-0.947 THz， with a relative bandwidth of 14.98%.

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• A high output power 340 GHz balanced frequency doubler designed based on linear optimization method

  LIU Zhi-Cheng, ZHOU Jing-Tao, MENG Jin, WEI Hao-Miao, YANG Cheng-Yue, SU Yong-Bo, JIN Zhi, JIA Rui

  2025,44(2):184-191 ,DOI: 10.11972/j.issn.1001-9014.2025.02.006

  Abstract: (4) HTML (0) PDF (2.58 MKB)(2)

  Abstract:

  In this paper， a linear optimization method（LOM） for the design of terahertz circuits is presented， aimed at enhancing the 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 improving 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 340 GHz frequency doubler was developed and measured. The results demonstrate that， across a bandwidth of 330 GHz to 342 GHz， the efficiency of the doubler remains above 10%， with an input power ranging from 98 mW to 141mW and an output power exceeding 13 mW. Notably， at an input power of 141 mW， a peak output power of 21.8 mW was achieved at 334 GHz， corresponding to an efficiency of 15.8%.

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Infrared Spectroscopy and Remote Sensing Technology

• Quantitative detection 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

  2025,44(2):192-202 ,DOI: 10.11972/j.issn.1001-9014.2025.02.007

  Abstract: (2) HTML (0) PDF (1.31 MKB)(9)

  Abstract:

  The presence of water in lunar materials can significantly impact the evolution of lunar geology and environment， as well as provide necessary conditions for the utilization of lunar resources. However， due to the limitations of lunar remote sensing methods， it is challenging to obtain direct evidence of water or determine its form of occurrence. Laser Raman spectroscopy， on the other hand， can provide valuable information on the type， distribution， and content of water in lunar materials without the need for illumination， sample pretreatment， or destructive measures. In this study， we utilized Raman spectroscopy to detect and quantify the water-containing characteristics of typical lunar rocks and minerals， including adsorbed water， ice， crystalline water， and hydroxyl-structured water. First， we used a 532 nm laser micro-Raman spectroscopy to identify and analyze the water-containing signals of various forms of water in lunar soil simulants. We then examined and analyzed the detection limits of adsorbed water， crystalline water， and hydroxyl-structured water in these simulants， as well as the relationship between their content and signal intensity. Finally， we employed linear regression （LR）， ridge regression （RR）， and partial least squares regression （PLSR） to quantitatively analyze the contents of these three forms of water in the lunar soil simulants. Our results demonstrate that the characteristic spectral peaks of the four forms of water in the lunar soil simulants can be clearly identified， with peak distribution regions located at 100-1 700 cm^-1 and 2 600-3 900 cm^-1 for the lunar soil components and water bodies， respectively. The spectral peaks of water are a combination of broad envelope peaks of hydrogen-bonded OH and sharp peaks of non-hydrogen-bonded OH stretching vibrations in varying proportions. The detection limits for 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. There is a linear relationship 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.

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

  ZHOU Ru-Jia, XIA Qing, ZHENG Qiong, ZHU Li-Hong, LI Jian-Hua, LI Bin, SONG Jia

  2025,44(2):203-210 ,DOI: 10.11972/j.issn.1001-9014.2025.02.008

  Abstract: (5) HTML (3) PDF (2.23 MKB)(3)

  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. With the purpose of weakening the influence of tides， a method of extracting coastal zone tidal flats by combining time-series Sentinel-2 images and tidal flat index was proposed. First， based on the Sentinel-2 time-series image data， we used the quantize synthesis method to generate high- and low-tide images， and then analyzed the spectral reluctance 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 was constructed. Secondly， the image spectral information and the tidal flat extraction index were input into a machine learning algorithm to realize fast and efficient extraction of the tidal flat. In addition， the study discussed the separability of the tidal flats index and the generalizability of the methodology. The results show that the tidal flat''s 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 had 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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• Urban tree species classification based on multispectral airborne LiDAR

  HU Pei-Lun, CHEN Yu-Wei, Imangholiloo Mohammad, Holopainen Markus, WANG Yi-Cheng, Hyypp? Juha

  2025,44(2):211-216 ,DOI: 10.11972/j.issn.1001-9014.2025.02.009

  Abstract: (0) HTML (0) PDF (1.01 MKB)(2)

  Abstract:

  Urban tree species provide various essential ecosystem services in cities， such as regulating urban temperatures， reducing noise， capturing carbon， and mitigating the urban heat island effect. The quality of these services is influenced by species diversity， tree health， and the distribution and the composition of trees. Traditionally， data on urban trees has been collected through field surveys and manual interpretation of remote sensing images. In this study， we evaluated the effectiveness of multispectral airborne laser scanning （ALS） data in classifying 24 common urban roadside tree species in Espoo， Finland. Tree crown structure information， intensity features， and spectral data were used for classification. Eight different machine learning algorithms were tested， with the extra trees （ET） algorithm performing the best， achieving an overall accuracy of 71.7% using multispectral LiDAR data. This result highlights that integrating structural and spectral information within a single framework can improve the classification accuracy. Future research will focus on identifying the most important features for species classification and developing algorithms with greater efficiency and accuracy.

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• Hperspectral remote sensing air traffic control monitoring based on contrails cloud proposal

  YANG Li-Feng, FENG Yan-Qing, WANG Jian-Yu

  2025,44(2):217-225 ,DOI: 10.11972/j.issn.1001-9014.2025.02.010

  Abstract: (1) HTML (1) PDF (929.00 KKB)(4)

  Abstract:

  To address the issues of low detection rate and high false alarm rate caused by complex background during sub-pixel aerial aircraft detection in hyperspectral remote sensing image， an aerial aircraft detection method was proposed based on contrails cloud proposal. Firstly， a hyperspectral semantic segmentation model was used to search for the contrails cloud， and regions of interests（ROIs） of aircraft were proposed to reduce invalid search ranges and suppress false alarms based on the contrails cloud. Secondly， an endmember extraction algorithm based on dictionary learning and semi-blind non-negative matrix factorization was proposed to improve the accuracy of aircraft endmember extraction for hyperspectral subpixels. Finally， verification experiments were carried out on the hyperspectral remote sensing image dataset of Gaofen-5 satellite. The results demonstrated that the algorithm proposed in this paper can effectively suppress false alarms in complex scenes， and significantly improve the detection rate and detection accuracy of sub-pixel aerial vehicles.

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• Simulation and evaluation of mid-infrared sea surface sun glint directional radiation

  ZHANG Zhen-Wu, WANG Ning, MA Ling-Ling, ZHANG Bei-Bei, ZHAO Yong-Guang, LI Wan

  2025,44(2):226-240 ,DOI: 10.11972/j.issn.1001-9014.2025.02.011

  Abstract: (1) HTML (1) PDF (4.65 MKB)(4)

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  The energy received in the mid-infrared （MIR） band at the sensor''s aperture includes both reflected solar energy and the emitted energy from Earth''s surface. Typically， the reflected solar energy in this band is weak. However， under certain conditions， such as in sun glint regions on the sea surface， the reflected solar energy detected by the MIR channel can be substantial. Currently， the application of sun glints physical models in the MIR band is not yet clear. This study investigates the accuracy of applying different visible light and shortwave infrared sun glint models in the MIR band to evaluate their applicability. The paper selects three models，namely Breon-Henriot， Ebuchi-Kizu， and Wu， to first evaluate the sensitivity of each sun glint model. Subsequently， four selected MODIS sun glint images were used as data sources， and ERA5 reanalysis data matched with satellite data was used to calculate atmospheric parameters. The solar radiation intensity reflected by the sea surface was computed using the three models. The accuracy of each model was then further validated with an MIR radiation transfer model. The results show that the Breon-Henriot model generally performs best in terms of correlation coefficient and root-mean-square error compared to MODIS measurements. These findings not only extend the application range of sun glint models in the MIR band but also enhance the MIR forward modeling system， providing new theoretical support for MIR radiation transfer and improving the effectiveness and accuracy of MIR remote sensing products in climate change monitoring and sea surface temperature dynamic analysis.

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Infrared Optoelectronic System and Application Technology

• Research progress on infrared temperature measurement for low emissivity objects

  HUANG Shan-Jie, ZHAO Jin-Song, WANG Ling-Xue, SONG Teng-Fei, XU Fang-Yu, CAI Yi

  2025,44(2):241-257 ,DOI: 10.11972/j.issn.1001-9014.2025.02.012

  Abstract: (2) HTML (1) PDF (1.35 MKB)(4)

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  Smooth objects such as metals， optical mirrors， and silicon wafers generally have extremely low emissivity and high reflectivity， and are called low emissivity objects. The extremely weak radiation from low emissivity objects will be submerged by the environmental radiation reflected from their surfaces. Infrared temperature measurement of low emissivity objects has always been a challenge in the field of infrared temperature measurement. Due to the continuously growing demand for non-contact temperature measurement of low emissivity objects in fields such as metal smelting， solar telescope thermal control， and semiconductor production， a large number of infrared temperature measurement methods for low emissivity objects have been proposed. First， this paper elaborates on the difficulties of the infrared temperature measurement of low emissivity objects and summarizes the temperature measurement methods currently used for low emissivity objects into five categories. Then， the basic principles and technical routes of each temperature measurement method were summarized， and the advantages and disadvantages of each temperature measurement method were analyzed in detail. Finally， the possible development directions of temperature measurement for low emissivity objects were discussed.

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• Aircraft altitude estimation method based on thermal infrared multispectral feature matching

  YANG Li-Feng, CHEN Zhuo, CHEN Fan-Sheng, WANG Jian-Yu

  2025,44(2):258-264 ,DOI: 10.11972/j.issn.1001-9014.2025.02.013

  Abstract: (2) HTML (2) PDF (2.30 MKB)(6)

  Abstract:

  The acquisition of aircraft altitude information is crucial for aviation safety and traffic control applications.Currently， it is difficult to obtain the altitude information of aircraft only through passive remote sensing methods. By combining atmospheric parameters retrieval and high-sensitivity infrared detection technology， space-borne remote sensing platforms can achieve accurate measurement of target thermal radiation information and have the potential for quantitative observation of aircraft characteristic information. 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 is 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 aircraft at different altitudes and flight states under different atmospheric conditions can be obtained by simulating. Thirdly， target spectral information can be extracted from remote sensing images and the altitude information can be estimated with 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.

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Interdisciplinary Research on Infrared Science

• Infrared remote sensing image super-resolution network by integration of dense connection and multi-attention mechanism

  XU Xin-hao, WANG Jun, WANG Feng, SUN Sheng-li

  2025,44(2):265-276 ,DOI: 10.11972/j.issn.1001-9014.2025.02.014

  Abstract: (3) HTML (2) PDF (1.60 MKB)(10)

  Abstract:

  Space-borne infrared remote sensing images have significant applications in environmental monitoring and military reconnaissance. Nonetheless， due to technological limitations， atmospheric disturbances， and sensor noise， these images suffer from insufficient resolution and blurred texture details， severely restricting the accuracy of subsequent analysis and processing. To address these issues， a new super-resolution generative adversarial network model is proposed. This model integrates dense connections with the Swin Transformer architecture to achieve effective cross-layer feature transmission and contextual information utilization while enhancing the model''s global feature extraction capabilities. Furthermore， the traditional residual connection is improved with multi-scale channel attention-based feature fusion， allowing the network to more flexibly integrate multi-scale features， thereby enhancing the quality and efficiency of feature fusion. A joint loss function is constructed to comprehensively optimize the performance of the generator. Comparative tests on different datasets demonstrate significant improvements with the proposed algorithm. Furthermore， the super-resolved images exhibit higher performance in downstream tasks such as object detection， confirming the effectiveness and application potential of the algorithm in space-borne infrared remote sensing image super-resolution.

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• Infrared small target detection algorithm via partial sum of the tensor nuclear norm and direction residual weighting

  SUN Bin, XIA Xing-Ling, FU Rong-Guo, SHI Liang

  2025,44(2):277-288 ,DOI: 10.11972/j.issn.1001-9014.2025.02.015

  Abstract: (1) HTML (1) PDF (1.84 MKB)(1)

  Abstract:

  Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background， an infrared small target detection method based on the tensor nuclear norm and direction residual weighting was proposed. Based on converting the infrared image into an infrared patch tensor model， from the perspective of the low-rank nature of the background tensor， and taking advantage of the difference in contrast between the background and the target in different directions， we designed a double-neighborhood local contrast based on direction residual weighting method （DNLCDRW） combined with the partial sum of tensor nuclear norm （PSTNN） to achieve effective background suppression and recovery of infrared small targets. Experiments show that the algorithm is effective in suppressing the background and improving the detection ability of the target.

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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, Bacao Fernando, SUN Chang-Xia, LI Yan-Ling

  2025,44(2):289-298 ,DOI: 10.11972/j.issn.1001-9014.2025.02.016

  Abstract: (1) HTML (1) PDF (1.96 MKB)(5)

  Abstract:

  The fusion of infrared and visible images should emphasize the salient targets in the infrared image while preserving the textural details of the visible images. To meet these requirements， an autoencoder-based method for infrared and visible image fusion is proposed. The encoder designed according to the optimization objective consists of a base encoder and a detail encoder， which is used to extract low-frequency and high-frequency information from the image. This extraction may lead to some information not being captured， so a compensation encoder is proposed to supplement the missing information. Multi-scale decomposition is also employed to extract image features more comprehensively. The decoder combines low-frequency， high-frequency and supplementary information to obtain multi-scale features. Subsequently， the attention strategy and fusion module are introduced to perform multi-scale fusion for image reconstruction. Experimental results on three datasets show that the fused images generated by this network effectively retain salient targets while being more consistent with human visual perception.

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• A lightweight dark object detection network for infrared images

  LI Zhao-Xu, XU Qing-Yu, AN Wei, HE Xu, GUO Gao-Wei, LI Miao, LING Qiang, WANG Long-Guang, XIAO Chao, LIN Zai-Ping

  2025,44(2):299-310 ,DOI: 10.11972/j.issn.1001-9014.2025.02.017

  Abstract: (3) HTML (1) PDF (1.55 MKB)(6)

  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， we proposed a lightweight dark object detection network， AirFormer. It only has 37.1 K parameters and 46.2 M floating-point operations on a 256×256 image. Considering the lack of infrared dark object detection dataset， the authors analyzed the characteristics of airplanes on thermal infrared satellite images， and then developed a simple simulation method for medium spatial resolution thermal infrared satellite images of civil aviation aircrafta， and constructed an infrared image weak target detection dataset IRAir using civil aviation aircraft as the simulation object. 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.

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• Infrared small target detection method based on nonconvex low-rank Tuck decomposition

  YANG Jun-Gang, LIU Ting, LIU Yong-Xian, LI Bo-Yang, WANG Ying-Qian, SHENG Wei-Dong, AN Wei

  2025,44(2):311-325 ,DOI: 10.11972/j.issn.1001-9014.2025.02.018

  Abstract: (1) HTML (0) PDF (2.21 MKB)(1)

  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 have achieved satisfactory detection performance in complex scenes， they need to define ranks in advance according to experience， and estimating the ranks too large or too small 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， a 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 the other advanced algorithms in detection performance and background suppression.

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光学生物医学融合与成像技术的应用

• Advances in time-stretching based coherent Raman spectroscopy techniques

  LIU Jun, MAN Zhi-Hao, LI Jing-Cheng, YANG Kang-Wen

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

  Abstract: (6) HTML (0) PDF (2.86 MKB)(3)

  Abstract:

  Coherent Raman spectroscopy and imaging technology， as a new type of label-free detection technology， has been widely used in biomedicine， material science and other fields by virtue of its high specificity and non-invasive advantages. In recent years， the combination of time stretching and coherent Raman spectroscopy effectively breaks through the limitations of traditional spectrometers in terms of sampling rate and spectral range， and provides a new idea for high-speed and broadband Raman spectroscopy and imaging. This paper firstly describes the basic principle of time stretching and its theory， and summarizes the results of the application of this technology in other fields； then systematically combs through the research progress of coherent Raman spectroscopy based on time stretching； finally， it looks forward to the future development of coherent Raman spectroscopy based on time stretching.

激光雷达创新与应用

• Application research and practice of GF-7 satellite in basin-level digital twin water conservancy

  Chen Jie, Li Guo-Yuan, Cui Xi-Ming, Yan Deng-Hua, Shen Dong-Liang, Zhang Bin, Liu Chang-Ru, Zhou Xiao-Qing, Yuan De-Bao

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

  Abstract: (30) HTML (0) PDF (3.02 MKB)(17)

  Abstract:

  The GF-7 satellite is equipped with China "s first operational earth observation laser altimeter and sub-meter optical stereo camera. High-precision laser altimetry data and sub-meter-level optical imagery data enable 1：10，000-scale stereoscopic mapping without ground control points， offering unique application advantages in large-scale spatial infrastructure construction for digital twin water resources management and water level monitoring of lakes and reservoirs. In the study， Miyun Reservoir is taken as the main research area. The GF-7 laser altimetry data and stereo image are used to extract the reservoir water level and the surrounding digital surface model（DSM）， and the application practice analysis is carried out. The results show that the absolute error of reservoir water level extracted based on laser altimetry data is less than 0.15 m， which is equivalent to the accuracy of the same type of foreign data. Based on the digital surface model， the water surface range prediction result F₁ is higher than 0.85， and the water volume change monitoring error is less than 3%， which can meet the requirements of related hydrological analysis applications. The relevant conclusions are of reference value for promoting the application of domestic GF-7 satellite laser altimetry and stereo image data in water conservancy， and better assisting the construction of basin level digital twin water conservancy.

光学生物医学融合与成像技术的应用

• Research progress on fiber-based laser sources for coherent Raman scattering imaging

  LI Jia-Ying, HU Dong-Sheng, ZHUANG Hao, LI Yi-Ze, JI Min-Biao

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

  Abstract: (37) HTML (0) PDF (1.03 MKB)(17)

  Abstract:

  Coherent Raman scattering microscopy is widely regarded as a powerful tool for solving biomedical problems due to its chemical specificity， label-free imaging capability， high spectral resolution and high sensitivity. However， the clinical application of coherent Raman scattering imaging technology has long been hindered by environmental sensitivity and large volume solid-state lasers. Ultrafast fiber lasers， with their compactness and stability， can effectively overcome these shortcomings. In this paper， different realization methods and research progress of fiber-based laser sources in coherent Raman scattering imaging are reviewed， including supercontinuum fiber source， soliton self-frequency shift fiber source， fiber optical parametric oscillator and synchronized fiber source， and the future development is prospected.

• YOLO-Fastest-IR: Ultra-lightweight thermal infrared face detection method for infrared thermal camera

  LI Xi-Cai, ZHU Jia-He, DONG Peng-Xiang, WANG Yuan-Qing

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

  Abstract: (98) HTML (0) PDF (2.01 MKB)(109)

  Abstract:

  This paper presents a high-speed and robust dual-band infrared thermal camera based on an ARM CPU. It is composed of a low-resolution long-wavelength infrared detector， a digital temperature and humidity sensor， and a CMOS sensor. In view of the phenomenon of large contrast between face and background in thermal infrared image， this paper we search for a suitable accuracy-latency tradeoff for thermal face detection and propose a tiny-lightweight detector named YOLO-Fastest-IR. Four different scale YOLO-Fastest-IR0 to IR3 thermal infrared face detectors based on YOLO-Fastest are designed. To train and test four tiny-lightweight models， a multi-user low-resolution thermal face database （RGBT-MLTF） is collected， and the four networks are trained. Experiments reveal that the lightweight convolutional neural network can also perform well in the thermal infrared face detection task. And the algorithm is superior to the existing face detection algorithms in positioning accuracy and speed， which is more suitable for deployment in mobile platforms or embedded devices. After obtaining the region of interest in the infrared image （IR）， the RGB camera is guided by the results of thermal infrared face detection， to realize the fine positioning of RGB face. The experimental results show that YOLO-Fastest-IR has a frame rate of 92.9 FPS on a Raspberry Pi 4B and can successfully locate 97.4% of the face in the RGBT-MLTF test set. The integration of infrared temperature measurement system with low cost， strong robustness and high real-time performance was ultimately achieved， the temperature measurement accuracy can reach 0.3 degrees Celsius.

毫米波与太赫兹技术

• Efficient multi-millijoule THz wave generation from laser interactions with a cylindrical GaAs waveguide

  Zahra Ghanavati, Reza Zangeneh Hamid

  Abstract: (44) HTML (0) PDF (305.38 KKB)(52)

  Abstract:

  This study involved a comprehensive investigation aimed at achieving efficient multi-millijoule THz wave generation by exploiting the unique properties of cylindrical GaAs waveguides as effective mediators of the conversion of laser energy into THz waves. Through meticulous investigation， valuable insights into optimizing THz generation processes for practical applications were unearthed. By investigating Hertz potentials， an eigenvalue equation for the solutions of the guided modes （i.e.， eigenvalues） was found. The effects of various parameters， including the effective mode index and the laser pulse power， on the electric field components of THz radiation， including the fundamental TE （transverse electric） and TM （transverse magnetic） modes， were evaluated. By analyzing these factors， this research elucidated the nuanced mechanisms governing THz wave generation within cylindrical GaAs waveguides， paving the way for refined methodologies and enhanced efficiency. The significance of cylindrical GaAs waveguides extends beyond their role as mere facilitators of THz generation； their design and fabrication hold the key to unlocking the potential for compact and portable THz systems. This transformative capability not only amplifies the efficiency of THz generation but also broadens the horizons of practical applications.PACS codes Each manuscript must be given 2-4 PACS

光学生物医学融合与成像技术的应用

• In Vivo Fluorescene Imaging in the Superior NIR-II Sub-window Using Clinical-Grade Fluorescent dye

  LI Jia-Yi, Zhang Pei-Jin, Xia Qi-Ming, Qian Jun

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

  Abstract: (58) HTML (0) PDF (1.40 MKB)(41)

  Abstract:

  NIR-II fluorescence imaging demonstrates significant advantages in biological imaging with its high signal-to-background ratio (SBR) and deep tissue penetration, showing broad application prospects in biomedical fields. The classification of NIR-II imaging windows facilitates the optimization of imaging processes. Among these, the 1400-1500 nm imaging window benefits from its unique water absorption characteristics, enabling effective suppression of scattering background and achieving high-contrast imaging. This study systematically evaluates the imaging potential of the 1400-1500 nm window through simulation studies and in vivo experiments. To advance the clinical translation of fluorescence imaging in the 1400-1500 nm window, indocyanine green (ICG), an organic small-molecule dye approved by the U.S. Food and Drug Administration (FDA), was employed as the fluorescent probe. Utilizing its extended fluorescence emission tail in the NIR-II region, high-contrast and high-resolution imaging of mouse vasculature and intestinal structures was achieved in the 1400-1500 nm window. Furthermore, in combination with methylene blue (MB), another FDA-approved agent, high-quality dual-channel NIR-II imaging was successfully implemented enabling precise localization of blood vessels and lymph nodes in mice. This research further explores the unique advantages of the 1400-1500 nm imaging window in biological imaging and its clinical application potential. It also provides valuable references for the clinical translation of NIR-II fluorescence imaging.

• Illuminating the Microscopic Mysteries of Enamel Demineralization through Terahertz Near-field Imaging

  Xiao Feng, Zhang Xiaoqiuyan, Cheng Li, Xu Xingxing, Zhang Tianyu, Tang Fu, Hu Tao, Hu Min

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

  Abstract: (94) HTML (0) PDF (903.30 KKB)(76)

  Abstract:

  Enamel demineralization often occurs in the early stage of dental caries. Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries. Terahertz （THz） technology， especially continuous wave （CW） THz near-field scanning microscopy （THz-SNOM） with its nanoscale resolution， can be promising in biomedical imaging. In addition， compared with traditional THz time-domain spectroscopy （TDS）， portable solid-state source as the emission has higher power and SNR， lower cost， and can obtain more precise imaging. In this study， we employ CW THz-SNOM to further break the resolution limitations of conventional THz imaging techniques and successfully achieve the near-field imaging of demineralized enamel at the nanoscale. We keenly observe that the near-field signal of the enamel significantly lowers as demineralization deepens， mainly due to the decrease in permittivity. This new approach offers valuable insights into the microscopic processes of enamel demineralization， laying the foundation for further research and treatment.

• Research on the Identification of Panax notoginseng Origin Using Terahertz Spectroscopy Combined with Convolutional Neural Networks

  WANG Jun-Tao, WANG Sheng-Feng, PENG Yan

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

  Abstract: (49) HTML (0) PDF (2.10 MKB)(83)

  Abstract:

  As a valuable Chinese herbal medicine, Panax notoginseng exhibits therapeutic efficacy and quality closely associated with its saponin content, which demonstrates significant geographical variations. To accurately authenticate the geographical origin and ensure medicinal quality, a novel method integrating terahertz precision spectroscopy with a convolutional neural network (CNN) algorithm was proposed. 40 Panax notoginseng samples from 4 regions in Yunnan Province, China—Honghe Autonomous Prefecture, Kunming, Qujing, and Wenshan Autonomous Prefecture—were analyzed using terahertz spectroscopy and high-performance liquid chromatography (HPLC). A CNN model was constructed and trained based on the acquired spectral and chromatographic data to classify the geographical origins. Experimental results revealed that the terahertz spectroscopy combined with the CNN model achieved a classification accuracy of 92.5%, significantly outperforming the 82.5% accuracy attained by the HPLC-CNN model. This finding highlights the potential of terahertz spectroscopy in component analysis and geographical traceability of herbal medicines, providing a novel scientific approach for rapid, non-destructive, and precise identification of Chinese medicinal materials.

• Rapid Quantitative Analysis of Antithrombotic Drug Plavix Using Terahertz Metamaterial

  ZHANG Jin-Jing, Liu Bing-Wei, LI Jia-Wei, WU Xu, SUN Li-Ying

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

  Abstract: (70) HTML (0) PDF (2.24 MKB)(74)

  Abstract:

  This study used a terahertz metamaterial sensor for the rapid and accurate detection of the antithrombotic drug Plavix， addressing the increasing demand for efficiency and sensitivity in drug content monitoring. Utilizing the terahertz vibration characteristics of Plavix， characteristic absorption peaks within the 1~3 THz band were identified. Based on these findings， a dual-polarization resonance metamaterial sensor was designed to simultaneously enhance the sensing signals of these characteristic absorption peaks. Experimental results indicate that the sensor attains a high level of fit （R²>0.97） for quantitative analysis in the quantitative detection of Plavix through the established two-indicator decision model. Consequently， the terahertz metamaterial sensing technology presented in this study exhibits superior performance in monitoring Plavix content and offers a new tool for clinical drug monitoring and broader biochemical sample analysis.

Application of Optical-Biomedical Fusion and Imaging Technology

• NIR-II Quantum Dot-Labeled Exosomes’Imaging in Treatment of Ischemic Peripheral Nerve Injury

  OGURA Shingo, SHAO Ke-Meng, Zhang Xiao, Li Hui-Zhu, Feng Si-Jia, WANG Yue-Ming, CHEN Jun, WU De-Hua, WO Yan

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

  Abstract: (97) HTML (0) PDF (1.92 MKB)(189)

  Abstract:

  Ischemia is a significant factor affecting the repair of peripheral nerve injuries， while exosomes have been shown to promote angiogenesis. To further investigate the detailed processes and efficacy of exosome therapy for ischemic peripheral nerve injuries， this study utilized glucose-modified near-infrared-II （NIR-II） quantum dots （QDs） to label adipose-derived stem cell exosomes （QDs-ADSC-Exos）， enabling long-term in vivo NIR-II imaging of exosome treatment for ischemic peripheral nerve damage. Experimental results confirmed that QDs can be used for non-invasive in vitro labeling of exosomes， with QDs-ADSC-Exos exhibiting strong fluorescence signals in the NIR-II window and demonstrating favorable NIR-II imaging characteristics in vivo. Notably， QDs-ADSC-Exos showed accumulation at the site of nerve injury in cases of ischemic peripheral nerve damage. Functional neurological assessments indicated that QDs-ADSC-Exos effectively promoted neural regeneration. This study highlights the potential of exosomes in treating ischemic peripheral nerve injuries and elucidates the spatiotemporal characteristics of exosome therapy， providing objective evidence for the further optimization of exosome-based treatment protocols.

光学生物医学融合与成像技术的应用

• A Review on the Research of Hyperspectral Detection Technology and Equipment for Key Quality Parameters of Tobacco Leaves

  HUANG Jin, ZHANG Li-Fu, SUN Xue-Jian, ZHAO Zhi-Peng, ZHAI Hao-Ran

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

  Abstract: (78) HTML (0) PDF (511.55 KKB)(45)

  Abstract:

  An overview is provided of the research progress in the application of hyperspectral detection technology for non-destructive testing of key parameters in tobacco leaf quality. Methods and equipment for the rapid detection of chemical components such as total sugar， reducing sugar， total nitrogen， nicotine， starch， chloride， and potassium in tobacco leaves using this technology are explored. The impact of different tobacco sample forms on spectral data is pointed out. The advantages and challenges of hyperspectral technology in applications such as field management， harvest optimization， and online grading in tobacco production are analyzed. The promising prospects of combining hyperspectral technology with artificial intelligence to build predictive models for tobacco leaf chemical composition are proposed. This combination provides scientific evidence and references for improving detection efficiency and quality in the tobacco industry.

• Exhaled Breath gas of CO detection based on quantum cascade laser absorption spectroscopy technique

  XU Shi-wen, WU Hua-Kun, ZHOU Chong-Qiu, WU Xiao-Yu, YANG Chao-Feng, WU Qiong, LIU Wen, SHAO Jie

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

  Abstract: (67) HTML (0) PDF (986.32 KKB)(49)

  Abstract:

  The concentration of exhaled CO as a biomarker for some diseases has attracted much attention， but CO concentration detectors had issues of low sensitivity and slow response time. Therefore， this paper used a quantum cascade laser with a central wavelength of 4.59 μm and a multi-pass cell of 3.8 m to build a high-sensitivity， fast-response exhaled CO measurement system based on absorption spectroscopy. The CO concentration was detected and analyzed using direct absorption （DAS） and wavelength modulation （WMS） techniques. The linearity of DAS is 0.998， and its detection limit reaches 3.68 × 10^-8. The linearity of WMS detection is 0.998 at CO concentrations below 6.00×10^-6， with the detection limit reaching 3.00×10^-9. The optimal integration times of 170 s and 250 s for DAS and WMS were obtained by Allan variance analysis， corresponding to detection limits of 2.00 × 10^-9 and 3.00 × 10^-10， respectively. Finally， 14 volunteers were tested for exhaled CO concentrations， and the results show that the system could distinguish between smokers and non-smokers， providing a scientific and effective tool for judging the smoking status of patients in smoking cessation clinics.

• Noninvasive terahertz near-field nano-imaging of mouse embryonic fibroblasts

  Zhong Qinyang, Zhang Xiaoqiuyan, Wang Ran, Zhang Tianyu, Tang Fu, Jiang Peidu, Hu Min

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

  Abstract: (59) HTML (0) PDF (1.36 MKB)(69)

  Abstract:

  Fibroblasts support a broad range of essential organ functions via microarchitectural， biomechanical， and biochemical cues. Despite great advances in fluorescence， photoacoustic conversion， and Raman scattering over the past decades， their invasiveness and limited spatial resolution hinder the characterization of fibroblasts in a single cell. Here， taking mouse embryonic fibroblasts （MEFs） as an example， we propose a novel noninvasive approach to investigate the compositional distribution of MEFs at the single-cell scale via terahertz （THz） nanoscopy. Compared to the topological morphology， THz nano-imaging enables the component-based visualization of MEFs， such as the membrane， cytoplasm， nucleus， and extracellular vesicles （EVs）. Notably， we demonstrate the real-space observation of the influence of rapamycin treatment on the increase of EVs in MEFs. Moreover， the line-cut and area-statistical analysis establishes the relationship between the topological morphology and the THz near-field amplitudes for different cellular components of MEFs. This work provides a new pathway to characterize the effects of pharmaceutical treatments， with potential applications in disease diagnosis and drug development.

• Research on discriminant method of temperature perturbation in blood glucose sensing by near-infrared spectroscopy

  ZHANG Yi-Ze, LIU Rong, YU Yue-Wen, ZHAO Dong-Jie, CHEN Wen-Liang, LI Chen-Xi

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

  Abstract: (51) HTML (0) PDF (1.40 MKB)(43)

  Abstract:

  Near-infrared spectroscopy is a type of molecular vibration spectroscopy. Temperature variations cause changes in molecular vibrations such as O-H and intermolecular forces such as hydrogen bonding， which lead to absorption spectral intensity and peaks changes， affecting the prediction accuracy of minor components such as blood glucose. To address the impact of temperature perturbation on spectral detection and modeling analysis， a temperature perturbation discrimination method based on aquaphotomics and two-trace two-dimensional correlation spectroscopy （2T2D-COS） was proposed. The 2T2D-COS analysis was applied to diffuse reflectance spectra of simulated solutions under temperature perturbation and varying glucose concentrations. Spectral features induced by changes in temperature and glucose concentration were successfully extracted， revealing distinct water spectral patterns under different perturbations. Quantitative analysis shows that a temperature change of 0.1°C is equivalent to a glucose concentration change of 45 mg/dL in terms of intensity. A temperature perturbation outliers discrimination model was further established based on raw spectra， water spectral features， and 2T2D-COS asynchronous spectra. The accuracy rates of the model based on 2T2D-COS asynchronous spectra are 95.83%. After removing outliers， the root mean square error of glucose concentration prediction is reduced by 51.89%. This workprovides a foundation for improving the accuracy of in vivo blood glucose detection using near-infrared spectroscopy.

• Research on the classification model of central precocious puberty based on features from functional near-infrared spectroscopy

  LI Ze-Ying, JIA Li-Fang, ZOU Ying-Xue, GAO Feng, LIU Dong-Yuan

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

  Abstract: (39) HTML (0) PDF (2.00 MKB)(47)

  Abstract:

  Central precocious puberty （CPP） is mainly caused by the premature activation of the hypothalamic-pituitary-gonadal axis， which leads to abnormal hormone levels and triggers structural and functional changes in the brain， making the neurovascular coupling mechanisms of children with CPP different from those of normal children in the task state. Addressing current limitations of clinical diagnosis， such as false negatives， interference from obesity， and physiological discomfort， this study utilized functional near-infrared spectroscopy （fNIRS） to analyze task-related brain activation characteristics in 167 children from Tianjin Hospital， including 85 normal children and 82 children with CPP. An auxiliary diagnostic model for CPP was established based on these analyses. It was found that the prefrontal activation areas during mental arithmetic （MA） were more in the normal group than in the CPP group， and the activation areas were more in females than in males. By selecting mean， variance， kurtosis， and skewness from the two channels with the highest frequency of correlation and the highest magnitude of negative correlation as input features， the constructed classification model achieved an accuracy rate of 79.1%. This study provides a new and important reference for the rapid screening and pathogenesis study of CPP.

• Terahertz wave and Raman spectroscopy technology application in traumatic brain injury

  LI Hai-Bin, WANG Yu-Ye, WANG Ze-Long, XU Bing-Feng, XU De-Gang, YAO Jian-Quan

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

  Abstract: (35) HTML (0) PDF (3.27 MKB)(52)

  Abstract:

  Traumatic brain injury is one of the most serious diseases that endanger human health. Sensitive and rapid detection method is a kind of powerful guarantee for the accurate and effective treatment of traumatic brain injury. In recent years, terahertz (THz) wave and Raman spectroscopy have broad application prospects in biomedical diagnosis and other fields due to their complementarity in technology. In this article, the researches of terahertz wave and Raman spectroscopy technology in traumatic brain injury detection were summarized in response to the needs and difficulties of traumatic brain injury diagnosis. Firstly, the development status of THz imaging and THz spectroscopy technology was introduced, and the applications of the two technologies in traumatic brain injury detection were also introduced, respectively. In addition, the principle and classification of Raman spectroscopy were summarized, and the research of Raman spectroscopy in the detection of traumatic brain injury tissues, body fluids, and biomarkers were discussed. Finally, the development trend of THz wave and Raman spectroscopy in the detection of traumatic brain injury was analyzed, which provides a new research idea for the application of THz wave and Raman spectroscopy in the rapid and accurate diagnosis of traumatic brain injury.

红外光电系统与应用技术

• Development of an active-detection mid-wave infrared search and track system based on

  ZHOU Pan-Wei, DING Xue-Zhuan, LI Fan-Ming, YE Xi-Sheng

  Abstract: (133) HTML (0) PDF (2.31 MKB)(83)

  Abstract:

  In order to meet the urgent need of infrared search and track applications for accurate identification and positioning of infrared guidance aircraft， an active-detection mid-wave infrared search and track system （ADMWIRSTS） based on "cat-eye effect" was developed. The ADMWIRSTS mainly consists of both a light beam control subsystem and an infrared search and track subsystem. The light beam control subsystem uses an integrated opto-mechanical two-dimensional pointing mirror to realize the control function of the azimuth and pitch directions of the system， which can cover the whole airspace range of 360°×90°. The infrared search and track subsystem uses two mid-wave infrared cooled 640×512 focal plane detectors for co-aperture beam expanding， infrared and illumination laser beam combining， infrared search， and two-stage track opto-mechanical design. In this work，the system integration design and structural finite-element analysis were conducted， the search imaging and two-stage track imaging for external scenes were performed， and the active-detection technologies were experimentally verified in the laboratory. The experimental investigation results show that the system can realize the infrared search and track imaging and the accurate identification and positioning of the mid-wave infrared guidance or infrared detection system through the echo of the illumination laser. The aforementioned work has important technical significance and practical application value for the development of compactly-integrated high-precision infrared search and track and laser suppression system， and has broad application prospects in the protection of equipment， assets and infrastructures.

红外物理与材料器件

• Performance requirement analysis of BIB detector in space target ground-based detection scenario

  GUO Xiao-Qing, LIANG Fang, WANG Ze-Wen, DONG Zuo-Ru, LIN Yi-Chao, ZHANG Chuan-Sheng, WANG Xiao-Dong

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

  Abstract: (129) HTML (0) PDF (902.56 KKB)(87)

  Abstract:

  The performance of detectors is one of the key factors for space target detection. In this paper, the performance requirements of blocked impurity band detectors for the ground-based detection scenario of space targets are analyzed. The theoretical calculation of background radiation and point target radiation is carried out by establishing the radiation transmission model of ground-based detection scenario. The correlation between radiation and detector performance is also analyzed. Taking space debris as a typical target and ground-based telescope as a carrying platform, the key performance requirements such as quantum efficiency, dark current, full well and specific detectivity are analyzed and calculated in the mid-latitude and high-altitude detection environment. This work lays a theoretical foundation for the detector structure design of ground-based detection.

• Mathematical model of pixel coupling in high-density planar InGaAs focal plane arrays

  DU Ai-Bo, YU Chun-Lei, SHAO Xiu-Mei, YU Jin-Ying, BAO Peng-Fei, LU Jin-Su, YANG Bo, ZHU Xian-Liang, LI Xue

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

  Abstract: (75) HTML (0) PDF (1.06 MKB)(78)

  Abstract:

  The application of InGaAs focal plane arrays (FPAs) requires high density and small pixel pitch. However, as the pixel pitch decreases, the pixel coupling becomes stronger. By fabricating 5 μm pitch InGaAs arrays with different scales, the pixel coupling effects in high-density InGaAs arrays were studied. Innovatively, matrix equations were introduced to describe the contributions of dark current from each part, and a mathematical model of pixel coupling was constructed, and the contributions of the dark current resulting from the coupling effects were quantitatively analyzed. The results indicated that at a bias voltage of -0.1 V, a reverse-biased pixels in the array can reduce the dark current of adjacent reverse-biased pixels by 21.39% of the pixel's initial dark current. In contrast, zero-biased pixels can increase the dark current of adjacent reverse-biased pixels by 219.42%. Based on this high-density focal plane pixel coupling model, the impact rules of pixel coupling on dark current have been summarized, providing new insights for dark current research in high-density InGaAs focal plane arrays.

• Precise calculation of radiation heat of cryogenic infrared detector Dewar

  ZENG Chang-hang, CHEN Jun, LI Si, YANG Xiu-hua, LI Qiu-yan, Ding Zhi-hong, TAO Chao-kun, XU Shi-chun

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

  Abstract: (89) HTML (0) PDF (1.02 MKB)(72)

  Abstract:

  The thermal load of the cryogenic infrared detector Dewar is a comprehensive indicator characterizing the adiabatic capacity of the Dewar. Radiative heat is a part of the thermal load. When calculating the radiative heat ，the traditional approach typically simplifies the Dewar to a coaxial cylindrical model. This simplified model differs significantly from the actual one and the traditional approach is incapable of computing the radiative heat transfer between surfaces where emissivity， transmittance， and reflectance vary with wavelength. To enhance the calculation accuracy of the Dewar"s radiative heat， based on the Monte Carlo principle， a 3D Studio Max modeling was employed， model information was extracted， and a program was developed， resulting in a set of general calculation programs for the Dewar"s radiative heat based on the radiation transfer factor. To preliminarily verify the accuracy of the calculation program， the cold side radiative heat of two types of experimental dewars was calculated according to the gray body assumption and compared with the measured values. The theoretical calculated value and measured value of the cold side radiation heat of experimental dewar 1 were 155 mW and 136 mW， respectively， with an error of 19 mW； the theoretical calculated value and measured value of cold side radiation heat of experimental dewar 2 were 87 mW and 79 mW， respectively， with an error of 8 mW. After initially testing the accuracy of the calculation program， the cold side radiative heat of an engineering typical 1K×1K long-wave dewar when the emissivity of the window facing it was 0.9 was calculated and measured experimentally. The theoretical calculated value was 127 mW， and the measured value was 110 mW， with an error of 17 mW.

毫米波与太赫兹技术

• Research on key technologies of 220 GHz integrated T/R module

  YAO Chang-Fei, WENG Lv-Tao, DONG Wen-Chao, CHEN Si-Yu, WANG Hao, WANG Wen-Wei, LIU Qiang, ZHU Ming

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

  Abstract: (76) HTML (0) PDF (1.82 MKB)(73)

  Abstract:

  A transceiver module operating at the 220 GHz frequency band was developed， consisting of three parts： a local oscillator chain， a transmitter chain， and a receiver chain， featuring high integration. A 218~226 GHz waveguide bandpass filter was designed to suppress spurious signals in the chain. The filter adopts a dual-mode resonant cavity structure to introduce a transmission zero on the left side of the passband， which suppresses the 214 GHz spurious signal by 60 dBc. An improved E-plane magic-T structure was used to form a four-way power combining amplifier to meet the requirement of transmit power. This module achieves a power combining efficiency of 72.5% and the output power is higher than 82 mW. The measured results show that in the 219.5~221 GHz frequency range， the transmit power is 82~95 mW， the noise figure of the receiver is less than 7.1 dB， the receive gain is 5.1~6.0 dB， and the volume of module is 65×70×30 mm3.

红外光谱与遥感技术

• Multimodal Remote Sensing Image Fusion Based on Self-supervised Pre-training and Cross-scale Contrastive Learning

  LI Zhao-Wei, FENG Shi-Yang, WANG Bin

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

  Abstract: (129) HTML (0) PDF (917.24 KKB)(115)

  Abstract:

  Self-supervised pre-training methods have strong capabilities in feature extraction and model transfer. However， current pre-training methods in multimodal remote sensing image （RSI） fusion only perform simple fusion operations such as concatenation on the extracted multimodal features without designing dedicated modules for the integration of multimodal information， leading to insufficient fusion of complementary information across modalities. Secondly， these methods do not consider and utilize the cross-scale consistency priors within RSIs， resulting in limited extraction and integration of multimodal remote sensing information， and thus the performance of various downstream tasks needs to be improved. In response to the above issues， a multimodal RSI fusion method based on self-supervised pre-training and cross-scale contrastive learning is proposed， which mainly includes three parts： 1） By introducing a cross-attention fusion mechanism to preliminarily integrate features extracted from different modalities， and then using encoder modules to further extract features， explicit aggregation and extraction of complementary information from each modality are achieved； 2） By introducing a cross-modality fusion mechanism， each modality can extract useful supplementary information from the features of all modalities， and reconstruct each modality’s input after separate decoding； 3） Based on the cross-scale consistency constraints of RSIs， cross-scale contrastive learning is introduced to enhance the extraction of single-modality information， achieving more robust pre-training. Experimental results on multiple public multimodal RSI fusion datasets demonstrate that， compared with existing methods， the proposed algorithm has achieved significant performance improvements in various downstream tasks. On the Globe230k dataset， our method achieves an average intersection over union （mIoU） of 79.01%， an overall accuracy （OA） of 92.56%， and an average F1 score （mF1） of 88.05%， and it has the advantages of good scalability and easy hyperparameter setting.

红外物理与材料器件

• 1550 nm InP/In_0.53Ga_0.47As laser power converters

  Zhang zongkun, Sun Yan, Hao Jiaming, Dai Ning

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

  Abstract: (106) HTML (0) PDF (1.79 MKB)(63)

  Abstract:

  We present the design， simulation， and experimental validation of a InP/In_0.53Ga_0.47As laser power converters for the wavelength of 1550 nm. By optimizing the thickness of the absorption layer and using a double-layer anti-reflection structure （SiO₂ and SiN）， By optimizing the thickness of the absorption layer and adopting a dual-layer anti-reflective structure （SiO₂ and SiN）， the device achieved an absorptance of 96% under 1550 nm laser irradiation， demonstrating insensitivity to angle variation and robust to wavelength shifts. The experimental results are in good agreement with the theoretical calculation results. The external quantum efficiency （EQE） reaches 92%. Under a laser power density of 47 mW/cm2， the cell’s conversion efficiency reached 23%. Further refinement of device processing is needed to reduce series and shunt resistances， thereby enhancing the overall efficiency of the laser photovoltaic cell. In addition， this study delves into the impact of cell area on the photovoltaic performance， providing optimization directions for the miniaturization of laser photovoltaic cells.

红外光谱与遥感技术

• Research on variable-speed scanning method for airborne area-array whisk-broom imaging system based on vertical flight path correction

  JIN Jia-Rong, HAN Gui-Cheng, WANG Chong-Ru, WU Ren-Fei, WANG Yue-Ming

  Abstract: (98) HTML (0) PDF (2.06 MKB)(91)

  Abstract:

  Airborne area-array whisk-broom imaging systems typically adopt constant-speed scanning schemes. For large-inertia scanning systems, constant-speed scanning requires substantial time to complete the reversal motion, reducing the system's adaptability to high-speed reversal scanning and decreasing scanning efficiency. This study proposes a novel sinusoidal variable-speed roll scanning strategy, which reduces abrupt changes in speed and acceleration, minimizing time loss during reversals. Based on the forward image motion compensation strategy in the pitch direction, we establish a line-of-sight (LOS) position calculation model with vertical flight path correction (VFPC), ensuring that the central LOS of the scanned image remains stable on the same horizontal line, facilitating accurate image stitching in whisk-broom imaging. Through theoretical analysis and simulation experiments, the proposed method improves scanning efficiency by approximately 18.6% at a 90° whisk-broom imaging angle under the same speed height ratio conditions. The new VFPC method enables wide-field, high-resolution imaging, achieving single-line LOS horizontal stability with an accuracy of better than 0.4 mrad. The research is of great significance to promote the further development of airborne area-array whisk-broom imaging technology toward wider fields of view, higher speed height ratios, and greater scanning efficiency.

毫米波与太赫兹技术

• A novel photonic crystal waveguide multifunctional light-emitting beaming device

  LIU Ze-kun, HUA Chang-zhou

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

  Abstract: (162) HTML (0) PDF (1.67 MKB)(65)

  Abstract:

  Based on two-dimensional triangular lattice photonic crystal， a multi-functional device of two-dimensional photonic crystal waveguide light-emitting beaming with integrated filtering function is designed， which can realize the fusion of outgoing light beaming and specific wavelength efficient filtering. The beam structure of the emitting light is similar to the grating structure， and the beam is in the state of clustering through the mutual interference principle between the multi-channel， which improves the radiation efficiency and distance of the emitting light. The finite difference time domain method can be used to obtain the effective propagation distance of 450 at the incident wavelength of 1.447. The structure design has a good beaming ability for incident light in the range of 1.435~1.465. At the same time， there are two hexagonal coupled filtering structures on either side of the waveguide， which are close to 98.4% and 97.3% transmission efficiency for incident light waves with a central wavelength of 1.490 and 1.510， respectively.The fusion structure successfully realizes the filtering and clustering functions.

• Fabrication and characterization of InGaAs/InAlAs photoconductive terahertz detection antenna with dynamic range exceeding 75 dB

  JIANG Qing-Nan, TAN Zhi-Yong, WAN Wen-Jian, FU Zhang-Long, XIA Yu, LI Min, CAO Jun-Cheng

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

  Abstract: (127) HTML (0) PDF (1.14 MKB)(63)

  Abstract:

  The photoconductive antenna is a very important device in the terahertz region and is widely used in terahertz time-domain spectroscopy technology. This article uses the molecular beam epitaxy method to grow Be-doped InGaAs/InAlAs superlattice as light absorbing materials for 1550 nm laser pumped photoconductive antenna for terahertz detection. The prepared materials have a sheet resistance greater than 10⁶ Ω/sq and an electron mobility of 216 cm²/（Vs）； The active mesa and electrode structure of the detection antenna are prepared using wet etching and magnetron sputtering processes， and the antenna chip is packaged on a PCB board. A detection antenna measurement system is built by employing a domestically produced 1550 nm femtosecond pump laser， and the detection antennas with electrode gaps of 40 μm and 60 μm were characterized； The measurement results indicate that the 60 μm antenna has a wider spectral width and power dynamic range， reaching 4.0 THz and 77.0 dB， respectively.

• Design of Commonly-Resonated Extended Interaction Circuits for Submillimeter-Wave Phase-Locked Oscillators

  Bi Liangjie, Li Hailong, Wang Bin, Meng Lin, Yin Yong

  Abstract: (56) HTML (0) PDF (1.92 MKB)(52)

  Abstract:

  In this paper, a scheme of commonly-resonated extended interaction circuit system based on high order TMn1 mode is proposed to lock the phases of two extended interaction oscillators (EIOs) for generating high power at G-band. Two separate EIOs are coupled through a specific single-gap coupling field supported by a designed gap waveguide with length (Lg), which form the phase-locked EIOs based on the commonly-resonated system. As a whole system, the system has been focused on with mode analysis based on different single-gap coupling field, mode hopping, which presents the variation of phase difference between the two-beam-wave interaction when changing the Lg. To demonstrate the effectiveness of the proposed circuit system in producing phase locking, we conducted particle-in-cell (PIC) simulations to show that the interesting mode hopping occurs with the phase difference of 0 and π between the output signals from two output ports, corresponding to the excitation of the TMn1 mode with different n. Simulation results show that 1) the oscillator can deliver two times of the output power obtained from one single oscillator at 220 GHz, 2) the two EIOs can still deliver output signals with phase difference of 0 and π when the currents of the two beams are different or the fabrication errors of the two EIO cavities are taken into account. The proposed scheme is promising in extending to phase locking between multiple EIOs, and generating higher power at millimeter-wave and higher frequencies.

红外光电系统与应用技术

• Infrared-NeRF: a low resolution thermal infrared light field 3D reconstruction method based on NeRF

  Huang Yi-Fan, Wang Rui, Deng Li-Ming, LI Jia-Jia, Li Xi-Cai

  Abstract: (282) HTML (0) PDF (1.95 MKB)(95)

  Abstract:

  This article proposes a three-dimensional light field reconstruction method based on neural radiation field （NeRF） called Infrared NeRF for low resolution thermal infrared scenes. Based on the characteristics of low resolution thermal infrared imaging， various optimizations have been carried out to improve the speed and accuracy of thermal infrared 3D reconstruction. Firstly， inspired by Boltzmann"s law of thermal radiation， distance was incorporated into the NeRF model for the first time， resulting in a nonlinear propagation of a single ray and a more accurate description of the physical property that infrared radiation intensity decreases with increasing distance. Secondly， in terms of improving inference speed， based on the phenomenon of high and low frequency distribution of foreground and background in infrared images， a multi ray non-uniform light synthesis strategy is proposed to make the model pay more attention to foreground objects in the scene， reduce the distribution of light in the background， and significantly reduce training time without reducing accuracy. In addition， compared to visible light scenes， infrared images only have a single channel， so fewer network parameters are required. Experiments using the same training data and data filtering method showed that compared to the original NeRF， the improved network achieved an average improvement of 13.8% and 4.62% in PSNR and SSIM， respectively， while an average decrease of 46% in LPIPS. And thanks to the optimization of network layers and data filtering methods， training only takes about 25% of the original method"s time to achieve convergence. Finally， for scenes with weak backgrounds， this article improves the inference speed of the model by 4-6 times compared to the original NeRF by limiting the query interval of the model.

Infrared Optoelectronic System and Application Technology

• Research on infrared imaging technology of gas plumes based on the vibe gases algorithm

  YANG Zhen, DING Shi-Hang, LIU Shi-Jie, CHEN li, ZHAO Bang-Jian, WANG Peng-Yu, WANG Ce-Yuan, XU Yu-Hui

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

  Abstract: (64) HTML (0) PDF (1.17 MKB)(93)

  Abstract:

  When a gas leak occurs, it propagates through space in the form of diffusion, typically forming a gas plume with dynamically stable concentration near the leakage source, which appears as a quasi-static region in infrared images; this characteristic often causes reduced detection accuracy of conventional moving object detection algorithms in these regions and makes it difficult to obtain the spatial concentration distribution of the gas. To address this issue, a Vibe Gases adaptive threshold detection algorithm based on the background subtraction method was proposed, which introduces improvements in two critical phases of gas plume imaging. During the foreground extraction phase, a foreground difference matrix is first constructed through gas detection logic and subjected to two-dimensional frequency mapping. Subsequently, the optimal threshold for separating the foreground and background is calculated by fitting a difference distribution function using the least squares method. In the background updating phase, a signal matrix of the foreground gas is established and processed with two-dimensional frequency mapping. The primary signal range is then extracted through frequency-based high-pass filtering, followed by delayed updates for pixels located within both the gas region and this primary signal range. The experimental results of infrared detection imaging under stable gas leakage conditions demonstrated that at a distance of 20 meters, the detection accuracy for ethylene reached 91.0% with an Intersection over Union (IoU) metric of 89.4%, while at 5 meters, the accuracy for detecting small leaks of sulfur hexafluoride was 81.3% with an IoU of 80.7%. The algorithm significantly improved the imaging quality of gas plumes, enhanced adaptive detection capabilities across diverse gases and scenarios, and effectively extracted spatial concentration distributions of gases.

毫米波与太赫兹技术

• The Realization and Research on the Verification of Millimeter Wave Phase Consistency

  LIU Jia-Qi, YANG Peng-Fei, ZHU Yi-Ming

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

  Abstract: (53) HTML (0) PDF (966.61 KKB)(67)

  Abstract:

  Phase consistency is produced under the requirements from the process of research， manufacture and realization in two-channel even muti-channels vector receivers. The requiring two-channel vector signals will be generated in this verification for stimulating the target systems or target sub systems， which can verify and emulate the performance in these systems or sub systems， and providing strong theories and technologies in the process of research and manufacture in systems. The specialized phase consistency measuring software controlling general instruments and specialized instruments， which can applied in the process of collocation， calibration， verification and signal generation for two-channel phase consistency signal system. The vector monitor and calibration for output network for specialized instrument has been studied and developed based on millimeter wave phase consistency， which including many technologies for realization and research like radio frequency amplitude-phase calibration， vector signal calibration， amplitude-phase measurement and restraint， and output signal threshold protection， meanwhile all testing parts are connected by Ethernet interface for feedback and control synchronization in the system.

• A Novel W-band Substrate Integrated Microstrip to Ultra-thin Cavity Filter Transition

  Cao Yi, Tang Xiaohong, Liu Yong, Cai Zongqi

  Abstract: (112) HTML (0) PDF (1.04 MKB)(62)

  Abstract:

  A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter. The structure is a new method of connecting microstrip circuits and waveguide filters， and this new structure enables a planar integrated transition from microstrip lines to ultra-thin cavity filters， thereby reducing the size of the transition structure and achieving miniaturization. The structure includes a conventional tapered microstrip transition structure， which guides the electromagnetic field from the microstrip line to the reduced-height dielectric-filled waveguide， and an air-filled matching cavity which is placed between the dielectric-filled waveguide and the ultra-thin cavity filter. The height of the microstrip line， dielectric-filled waveguide and the ultra-thin cavity filter are the same， enabling seamless integration within a planar radio-frequency （RF） circuit. To facilitate testing， mature finline transition structures are integrated at both ends of the microstrip line during fabrication. The simulation results of the fabricated microstrip to ultra-thin cavity filter transition with the finline transition structure， with a passband of 91.5-96.5 GHz， has an insertion loss of less than 1.9 dB and a return loss lower than -20 dB. And the whole structure has also been measured which achieves an insertion loss less than 2.6 dB and a return loss lower than -15dB within the filter"s passband， including the additional insertion loss introduced by the finline transitions. Finally， a W-band compact up-conversion module is designed， and the test results show that after using the proposed structure， the module achieves 95 dBc suppression of the 84 GHz local oscillator. It is also demonstrated that the structure proposed in this letter achieves miniaturization of the system integration without compromising the filter performance.

Millimeter Waves and Terahertz Technology

• Millimeter-Wave Modeling based on Transformer model for InP High Electron Mobility Transistor

  ZHANG Ya-Xue, ZHANG Ao, GAO Jian-Jun

  Abstract: (66) HTML (0) PDF (992.01 KKB)(60)

  Abstract:

  In this paper， the small-signal modeling of the Indium Phosphide High Electron Mobility Transistor （InP HEMT） based on the Transformer neural network model is investigated. The AC S-parameters of the HEMT device are trained and validated using the Transformer model. In the proposed model， the eight layers transformer encoders are connected in series and the encoder layer of each Transformer consists of the multi-head attention layer and the feed-forward neural network layer. The experimental results show that the measured and modeled S-parameters of the HEMT device match well in the frequency range of 0.5-40 GHz， with the errors versus frequency less than 1%. Compared with other models， good accuracy can be achieved to verify the effectiveness of the proposed model.

Application of Optical-Biomedical Fusion and Imaging Technology

• Alignment-Optimised Coaxial Visible-NIR-II Dual-Channel Surgical Navigation System and Its Clinical Application in Blood-Supply Assessment

  Zhang Yu-Huang, Liu Xiao-Long, Sun Si-Ying, Fan Xiao-Xiao, Lin Hui, Qian Jun

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

  Abstract: (168) HTML (0) PDF (1.64 MKB)(392)

  Abstract:

  Fluorescence imaging in the second near-infrared window (NIR-II, 900-1880 nm) offers high signal-to-background ratio (SBR), enhanced definition, and superior tissue penetration, making it ideal for real-time surgical navigation. However, with single-channel imaging, surgeons must frequently switch between the surgical field and the NIR-II images on the monitor. To address this issue, a coaxial dual-channel imaging system that combines visible light and 1100 nm long-pass (1100LP) fluorescence was developed. The system features a customized coaxial dual-channel lens with optimized distortion, achieving precise alignment with an error of less than ±0.15 mm. Additionally, the shared focusing mechanism simplifies operation. Using FDA-approved indocyanine green (ICG), the system was successfully applied in dual-channel guided rat lymph node excision, and blood supply assessment of reconstructed human flap. This approach enhances surgical precision, improves operational efficiency, and provides a valuable reference for further clinical translation of NIR-II fluorescence imaging.

• Terahertz detector based on side-gate AlGaN/GaN HEMT for resonant detection

  JIN Chen-Yang, KANG Ya-Ru, LI Ye-Ran, YAN Wei, NING Jin, ZHAO Yong-Mei, LI Zhao-Feng, YANG Fu-Hua, WANG Xiao-Dong

  Abstract: (2) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In high-electron-mobility transistor (HEMT) terahertz detectors, an excessively wide gate can generate oblique modes in the channel, resulting in weakened resonant detection signals and a broadened resonance peak. To address this issue, a side-gate HEMT (EdgeFET) structure was proposed. A resonant detection model for the side-gate device was established based on the hydrodynamic equations of the two-dimensional electron gas (2DEG) in conventional HEMT. A side-gate HEMT detector was fabricated, and terahertz resonant detection experiments were conducted at 77 K. The experimental results indicated that EdgeFET demonstrated distinct resonant responses at 77 K, with the resonant responsivity reaching 3.7 times the maximum non-resonant responsivity. The experimental data were fitted using the theoretical model to validate its accuracy. These results strongly confirm the effectiveness of EdgeFET in enhancing the resonant performance of the detector, providing a new technological approach for the development of next-generation high-performance terahertz detectors.

  • 1
• High-Performance Terahertz Detectors Based on Large-Area Semimetallic Platinum Telluride (PtTe2)

  HUANG De-Bao, ZHOU Wei, HUANG Jing-Guo, QIU Qin-Xi, JIANG Lin, YAO Niang-Juan, GAO Yan-Qing, HUANG Zhi-Ming

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

  Abstract:

  Terahertz (THz) detectors, serving as the pivotal components for photoelectric conversion, constitute one of the fundamental building blocks in modern information society. Large-area PtTe2 thin films were synthesized via chemical vapor deposition (CVD), enabling the fabrication of THz detectors with varied channel lengths. Characterization results demonstrate that the device response exhibits linear dependence on both bias voltage and incident power, while the responsivity shows an inverse proportionality to channel length and operational frequency. The observed device characteristics align well with theoretical calculations based on the electromagnetic induced well (EIW) mechanism. Notably, EIW-based devices achieve a rapid response time of ~7.6 μs, with noise equivalent power (NEP) below 7.9×10-15 W/Hz0.5 and specific detectivity (D*) exceeding 9×1010 cm·Hz0.5/W under limited bias conditions. These performance metrics surpass those of previously reported semimetallic PtTe2-based detectors.

  • 1
• Millimeter Wave Imaging of Range Migration Algorithm with Adaptive Background Filtering

  CHENG Zhi-Hua, ZHOU Ran, WANG Meng, YU Tao, WANG Yu-Lan, YAO Jian-Quan

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

  Abstract:

  This paper proposes a novel Range Migration Algorithm (RMA) integrated with an adaptive background filtering method specifically designed for near-field millimeter-wave imaging scenarios where targets are in close proximity to background structures. This method simulate the attention distribution mode of the human visual system which is used in Artificial Intelligence (AI) and called Attention Mechanism. Based on the concept of static clutter filtering, the frequency-domain signals of the scanning aperture are divided into grid cells. Background scattering functions are established by analyzing the motion processes within each cell, and background interference is linearly filtered out. An analysis of the manifestation of background scattering interference within the algorithm is carried out, and the impact of the grid cell dimension on the imaging quality is investigated. Experimental results that the proposed method exhibits the capability to enhance the signal-to-noise ratio of both the target and the background. It effectively suppresses the background interference leading to a more prominent image, meanwhile without incurring a prohibitive computational load. The method offers a novel solution for improving the performance of millimeter-wave imaging technology in practical applications.

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• Fabrication of flexible, low-loss and high-reliability PI mid-infrared hollow optical fiber and investigation of its CO2 laser transmission performances

  YU Shuo-Ying, ZHU Run-Miao, LIU Sheng, ZHA Zhi-Peng, ZHANG Qing-Tian, HOU Guang-Ning, FEI Ying-Di, LIU Shao-Hua, JING Cheng-Bin, CHU Jun-Hao

  Abstract: (25) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Hollow optic fiber delivery of CO2 and other mid-infrared lasers still faces several challenges in terms of transmission loss, bending flexibility and reliability, which limits its applications in laser medicine, flexible industrial processing, and intelligent sensing. A flexible, low-loss mid-infrared hollow fiber with enhanced PI/Ag/AgI interfacial bonding strength has been developed by utilizing plasma activation of polyimide (PI) structural tubing and a dynamic liquid-phase deposition process. The results showed that after plasma treatment, the N-C bonds on the surface of PI were converted to N-O bonds and active groups such as carboxyl were formed. This results in enhancement of surface hydrophilicity and the interfacial bonding strength between PI and Ag/AgI layers (from level 0 to level 2) without noticeably increasing surface roughness. The as-fabricated PI hollow fiber (ID=2 mm) exhibited a low-loss transmission window within 8~15 μm wavelength range, achieving a linear transmission loss as low as 0.05 dB/m at 10.6 μm. When bent 180° with a radius of 20 cm, the loss increased only to 0.55 dB/m. The fiber could deliver a 30 W CO2 laser beam for 300 s at 150°C without damage. After 400 min of vibration testing and 120 min of high-low temperature aging (-196°C/150°C), the transmission loss remained stable, showing its value for practical applications.

  • 1
• Peak Separation and Small Signal Modeling Analysis of Abnormal Shift in the transconductance curve in InAs Composite Channel HEMT

  GONG Yong-Heng, CHEN Yu-Xuan, SHI Jing-Yuan, ZHANG Da-Yong, SU Yong-Bo, DING Wu-Chang, JIN Zhi, Ding Peng

  Abstract: (25) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In this work, 100 nm gate-length InP-based high electron mobility transistors (HEMTs) with a composite InGaAs/InAs/InGaAs channel are fabricated. DC measurements indicate that the InAs channel enhances transconductance but shifts the peak point toward lower?Vgs?under high?Vds?bias. Peak separation analysis reveals the DC transconductance curve is composed of two components: the gate-controlled transconductance and the impact-ionization-induced additional transconductance. Further analysis demonstrates that the anomalous shift originates from channel impact ionization intensity variation, which is caused by changes in the gate-drain electric field rather than carrier density in the channel. Two additional current sources were introduced in the small-signal model to characterize the impact-ionization-induced transconductance, and the numerical variation trends of their parameters are consistent with the peak separation results, which validates the mechanism's correctness. RF measurements confirm that the DC transconductance enhancement does not effectively improve RF characteristics, which is attributed to the ionization-induced transconductance having a time constant significantly larger than that of conventional transconductance components. These findings provide a theoretical foundation for controlling impact-ionization and improving effective transconductance, ultimately optimizing InAs channel HEMT design.

  • 1
• Room-temperature Highly sensitive Bi₂Te₃ Terahertz Detector Based on Hot-carrier Photothermoelectric Effect

  CAI Miao, WANG Xing-Jun, GUO Xu-Guang

  Abstract: (35) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  High-performance uncooled terahertz (THz) detectors have a wide range of applications in many technological fields, such as high-rate data communications, real-time imaging, spectroscopy and sensing. However room-temperature THz detectors with high sensitivity and fast response capability are still rare. In recent years, the hot-carrier photothermoelectric (PTE) effect in two-dimensional (2D) materials has been found to be useful for room-temperature, high-speed, and highly sensitive photodetection in the THz and long-wave infrared radiation. In this study, the authors constructed a room-temperature THz detector based on the high-performance 2D layered thermoelectric material Bi2Te3, which employs a bow-tie antenna as an asymmetric light coupler and utilizes the hot-carrier PTE effect to achieve THz detection in zero-bias mode. The results show that the Bi2Te detector exhibits excellent THz detection performance, with a responsivity and noise equivalent power (NEP) of 0.45 A/W, 17 pW/Hz^1/2, and a fast response time of 12 μs under 100 GHz radiation, respectively. This work demonstrates the promising application of Bi2Te3 THz detectors based on the hot-carrier PTE effect in realizing high-performance uncooled THz detectors.

  • 1
• Continuous Wave Operation of Terahertz Quantum Cascade Wire Lasers with Dual Coupled Gratings

  TAN Cheng, ZOU Ting-Ting, ZANG Shan-Zhi, WANG Kai, GAN Liang-Hua, CAO Chen-Tao, CHEN Bing-Qi, CHEN Hong-Tai, ZHANG Yue-Heng, FANG Yu-Long, XU Gang-Yi

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

  Abstract:

  We demonstrate terahertz quantum cascade (THz-QC) wire lasers based on dual coupled gratings that achieve continuous-wave (CW) operation near liquid nitrogen temperatures with a low-divergence Gaussian-like beam profile. Our configuration circumvents the effective refractive index constraint, significantly enhancing fabrication efficiency while retaining the key advantages of low power consumption and high heat dissipation efficiency. By engineering the photonic band structure of the coupled gratings, the laser operates on two supermodes. For Supermode #1, grating 1 serves as the master oscillator while grating 2 functions as a phased antenna array, featuring a collimated beam. For Supermode #2, grating 2 is the main oscillator and simultaneously provides a collimated beam, while grating 1 offers high reflectivity. Both supermodes exhibit high cavity quality factors and low beam divergence, achieved with a significantly reduced gain area. Experimentally, both supermodes were observed, and the optimized laser produces a collimated Gaussian beam with divergence angles of 12°×18° and an optical power of 1.04 mW. The threshold power consumption and thermal resistance are as low as 2.62 W and 8.5 mK/W/cm2, respectively, resulting in a maximum CW operating temperature of 78.0 K. This work offers a more accessible route for low-divergence, low-power-consumption, high-thermal-dissipation-efficiency THz-QCLs with enhanced CW operation at elevated temperatures.

  • 1
• Field-Enhanced Ge-Based PIN Structured Blocked Impurity Band Infrared Detectors in Weakly Ionized Regions

  Liu Chixian, Tianye-Chen, Zexin-Wang, Qingzhi-Hu, Wei-Dou, Xiaoyan Liu, Jingwei-Ling, Changyi-Pan, Jiaqi-Zhu, Peng-Wang, Huiyong-Deng, Hong-Shen, Ning-Dai

  Abstract: (51) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  A novel germanium （Ge） based blocked-impurity-band （BIB） infrared detector with a planar PIN structure was developed, using near-surface processing technique to fabricate the target and electrode contact regions. The detector demonstrates significant rectifying characteristics, exhibiting extremely low dark current under reverse bias, and its working temperature is extended to 15 K. At this temperature, the detector maintains a stable detectivity of 6 × 1012 cm·Hz1/?·W?1 within the reverse bias voltage range of 0 to -5 V. Through band structure analysis, the dark current mechanism and the impact of temperature variation on optical response were discussed in detail, and the working principle based on the low-temperature weak ionization region was proposed. Additionally, tests of the detector’s blackbody response current and detectivity were systematically measured, and the mechanism of maintaining high performance at elevated working temperatures was clarified. The result provides innovative insights for enhancing the temperature performance of Ge-based BIB detectors and offers theoretical and experimental support for the design and application of future infrared detectors.

  • 1
• Effect of mixed-period gratings on the photoresponse bandwidth of long-wavelength quantum well infrared photodetectors

  TIAN Ya-Ping, LI Zhi-Feng, LI Ning, LI Xiang-Yang, XU Jin-Tong

  Abstract: (41) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The expansion of response bandwidth is an important direction in the development of quantum well infrared photodetectors. Using quantum well material with the peak response wavelength at 10.55 μm, the diffraction grating structure in the 30 μm center distance quantum well infrared detector is optimized, and six different combinations of the mixed-period gratings are obtained by mixing three grating structures with the period of 2.80, 3.50, and 4.25 μm within a single photosensitive pixel. Photoresponse spectroscopy tests show that the response bandwidth of the mixed-period grating can be broadened from 1.20 μm to 1.91 μm by up to 60% compared to a single-period grating, while the blackbody responsivity decreases by only 12%.

  • 1
• The Study of Electrical Properties of Type-II InAs/GaSb Superlattices

  xiangtaiyi, WANG NAN, HUANG MING, CHAI Xu-Liang, CHEN Jian-Xin

  Abstract: (39) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In order to investigate the electrical properties of InAs/GaSb type-II superlattices, a lattice-matched AlAsSb electrical isolation layer was grown between the GaSb substrate and the InAs/GaSb type-II superlattice epitaxial material to suppress the conductive effect of the substrate. Temperature-dependent Hall measurements revealed that the undoped superlattice exhibited N-type conductivity. As the P-type doping concentration increased, a compensation doping phenomenon was observed, with the occurrence of conductivity type transitions at 95 K and 230 K, respectively. Below the transition temperatures, P-type conductivity was exhibited, while above the transition temperatures, the material exhibited N-type conductivity. The phenomenon was analyzed using the Fermi level model, and the results indicated that the transition temperature for conductivity type changes increased with increasing doping concentration.

  • 1
• High-Resolution Defect Detection in Optoelectronic Device via Scanning Imaging Technique

  HU Er-Tao, LIU Jia-Wei, SHAO Peng, XIN Hao, CAI Qing-Yuan, DUAN Wei-Bo, CHEN Liang-Yao

  Abstract: (66) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Photocurrent scanning imaging (mapping) technology is a key technique in the research of solar cells and photodetectors. However, traditional galvanometer-driven beam scanning methods are limited by a restricted scanning range and image distortion. To address these shortcomings and meet the need for testing the photocurrent uniformity of large-area optoelectronic devices, an automated photocurrent mapping testing system has been developed based on optical component scanning. This system offers a large imaging range, high spatial resolution, high stability, and low cost. With its high-precision mode, it can achieve sub-micron geometric positioning (subdivision number 6400, scanning step size 0.625 μm), fulfilling both large-area scanning requirements and providing high-resolution testing. Moreover, its simple structure greatly reduces the overall cost of the mapping system. Using a silicon solar cell sample with surface covered by a “南” (south) character paper or a encoder strip mask, it was demonstrated that the scanning range exceeds 10×10 mm2, with a spatial resolution of 0.6 μm. The system was also used to characterize the surface photocurrent images of Cu?ZnSnS? and Cu?ZnSn(S,Se)? solar cells. The results show that the Cu?ZnSnS? cell contains more defects, while the Cu?ZnSn(S,Se)? cell exhibits a more uniform surface photocurrent response with fewer defects. These findings contribute to the optimization of solar cell fabrication processes.

  • 1
• Research on stress adaptability of InAs/GaSb type Ⅱ superlattice long-wave focal plane infrared detectors

  XUE Yong, XU Qing, HUANG Min, WANG Zhen, LIANG Zhao-Ming, XU Qing-Qing, BAI Zhi-Zhong, CHEN Jian-Xin

  Abstract: (51) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The superlattice long-wavelength infrared focal plane detectors operate at low-temperatures. The differences in the thermal expansion coefficients among the various material layers of the detectors can lead to deformation and generate thermal stress, which in turn affects the optoelectrical performances of the detector. This study designed two structural modules to achieve the regulation of stress in the superlattice detectors. The changes in dark current and spectral response of InAs/GaSb type II superlattice long-wave infrared focal plane detectors under different stress conditions were explored. The research indicates that within the stress range of -10.7 MPa to 131.9 MPa, the variations in the optoelectrical performance of the detector is small. The detector was subjected to a temperature shock test, and it demonstrated high reliability. Our research results provide guidance for the structural design of InAs/GaSb type II superlattice long-wave infrared focal plane detectors and offer a basis for their performance and reliability assessment.

  • 1
• Study on the performance and parameters of interdigitated GaAs photoconductive terahertz radiation source

  ZHANG yu-song, Shi Wei, LI yi-fan, Hou Lei, LI huan-lin

  Abstract: (56) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Optimizing the substrate material and electrode structure of photoconductive antennas is crucial to improving their performance in radiating terahertz waves. Compared with traditional photoconductive antennas (PCA), interdigitated photoconductive antennas (IPCA) can build multiple array elements in a smaller photosensitive area and have superior radiation performance. In this paper, six types of IPCA with different number of array elements and electrode gaps were designed and developed. The reverse electric field between adjacent electrodes was eliminated by blocking metal layers. The radiation characteristics and polarization characteristics of IPCA were compared with traditional PCA (parallel electrode antenna and bowtie antenna). The changes of the radiation characteristics of IPCA with the number of array elements, electrode gap, pump light energy and bias electric field were further studied. Experimental results show that the THz pulse radiation amplitude of the 40-element IPCA is 30 times higher than that of a single antenna.

  • 1
• A Multi-Attention Mechanism U-Net Neural Network for Image Correction of PbS Quantum Dot Focal Plane Detectors

  Hanting Wang, Di Yun-Xiang, Xingyu Qi, Yingzhe Sha, Yahui Wang, Lingfeng Ye, Weiyi Tang, Ba Kun, Wang Xu-Dong, Huang Zhang-Cheng, Chu Jun-Hao, Shen Hong, Wang Jian-Lu

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

  Abstract:

  Near-infrared image sensors are widely used in fields such as material identification, machine vision, and autonomous driving. Lead sulfide colloidal quantum dot-based infrared photodiodes can be integrated with silicon-based readout circuits in a single step. Based on this, we propose a photodiode based on an n-i-p structure, which removes the buffer layer and further simplifies the manufacturing process of quantum dot image sensors, thus reducing manufacturing costs. Additionally, for the noise complexity in quantum dot image sensors when capturing images, traditional denoising and non-uniformity methods often do not achieve optimal denoising results. For the noise and stripe-type non-uniformity commonly encountered in infrared quantum dot detector images, a network architecture has been developed that incorporates multiple key modules. This network combines channel attention and spatial attention mechanisms, dynamically adjusting the importance of feature maps to enhance the ability to distinguish between noise and details. Meanwhile, the residual dense feature fusion module further improves the network"s ability to process complex image structures through hierarchical feature extraction and fusion. Furthermore, the pyramid pooling module effectively captures information at different scales, improving the network"s multi-scale feature representation ability. Through the collaborative effect of these modules, the network can better handle various mixed noise and image non-uniformity issues. Experimental results show that it outperforms the traditional U-Net network in denoising and image correction tasks.

  • 1
• Design and fabrication of pixel-level infrared metalens arrays for light field control

  ZHANG Feng, WANG Fang-Fang, ZHOU Jian, YING Xiang-Xiao, ZHOU Yi, CHEN Jian-Xin

  Abstract: (41) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Metalenses，with their unique optical field modulation characteristics and remarkable advantages of high integration and miniaturization, have broad applications in the integrated imaging system of lightweight and small-sized optoelectronic chips. In this paper, a metalens structure for pixel-level integrated infrared focal plane applications was designed. The preparation of the structure adopted a method combining stepper lithography technology and Inductively Coupled Plasma (ICP) etching process. Through a systematic optimization of etching parameters, including gas flow rate, working pressure, and power, the loading effect was effectively suppressed and the standard deviation of the etching rate was decreased from 0.205% to 0.073%. Finally, a highly uniform metalens array was fabricated, with a pixel center distance of 30 μm, an array of 640×512, and a maximum aspect ratio of 3.42 of Si pillars. The focusing distance for 4.3 μm wavelength infrared light is 35 μm. The measured optical field convergence efficiencies, within radial ranges of 10 μm and 20 μm in the centra area at the focal length, are 66.4% and 84.9%, respectively. The optical field energy is increased by 5.98 times and 1.91 times, respectively, compared with that without the integrated metalens within the same area range. This study will provide the structural design and processing foundation for the integration of pixel-level metalens arrays with infrared chips.

  • 1
• High performance multifunction integrated optic circuits base on thin-film lithium niobate

  Qu Baiang, GUO Hong-Jie, YANG Yong-Kang, CHEN Wen-Bin, GUO Wen-Tao, TAN Man-Qing

  Abstract: (64) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  This paper introduces an innovative Multifunction Integrated Optic Circuit (MIOC) design utilizing thin-film lithium niobate, surpassing traditional bulk waveguide-based MIOCs in terms of size, half-wave voltage requirements, and integration capabilities. By implementing a sub-wavelength grating structure, we achieve a Polarization Extinction Ratio (PER) exceeding 29 dB. Furthermore, our electrode design facilitates a voltage-length product (VπL) below 2 V·cm, while a double-tapered coupling structure significantly reduces insertion loss. This advancement provides a pivotal direction for the miniaturization and integration of optical gyroscopes, marking a substantial contribution to the field.

  • 1
• Moving Mirror Speed Compound Control of the Fourier Transform Spectrometer Based on T-method

  HUANG Ying, DUAN Juan, GUO Qian, DING Lei, HUA Jian-Wen

  Abstract: (27) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The Fourier transform spectrometer (FTS) is a precision infrared detection instrument. It adopts Michelson interference splitting, and the moving mirror is one of the core components. The uniformity and stability of the moving mirror’s speed directly affect the quality of the subsequent interferogram, so it is necessary to carry out high-precision motion control of the moving mirror. For some FTS with moving mirror in low-speed motion, the traditional M-method can no longer meet the requirements of speed measurement accuracy. In addition, when the moving mirror moves at a low speed, the speed stability is more easily affected by external mechanical disturbance. Based on the stability requirement of the low-speed moving mirror, this paper studies the motion control of the moving mirror based on the T-method measuring speed. It proposes a high-precision algorithm to obtain the measured and expected value of the velocity. By establishing the mathematical model and dynamic equation of the controlled object, the speed feedforward input is obtained, and then the compound speed controller based on the feedforward control is designed. The control algorithm is implemented by the FPGA hardware platform and applied to the FTS. The experimental results show that the error of the peak-to-peak velocity is 0.0182, and the error of the root mean square (RMS) velocity is 0.0027. To test the anti-interference ability of the moving mirror speed control system, 5mg sine excitation force is applied in the motion direction of the moving mirror on the FTS for frequency-fixed scanning. The frequency range is 2-200Hz. The experimental results show that under the excitation, the maximum error of the peak-to-peak velocity is 0.0679, and the maximum error of the RMS velocity is 0.0205. The speed stability of the moving mirror can still meet the performance requirements of the FTS. This design provides a technical means for realizing the speed control of the moving mirror with low speed and high stability. Also it makes the FTS have wider applications.

  • 1
• Aircraft contrail detection based on satellite-borne hyperspectral images

  XIE Shu-Xin, LI Peng-Fei, ZHAO Si-Wei, LIAN Xiao-Ying, SUN De-Xin

  Abstract: (43) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Existing methods for detecting aircraft contrails primarily relied on the radiance or temperature differences between specific channels in multispectral images. However, they did not fully exploit the potential of spectral features. The advancement of satellite-borne hyperspectral imaging technology has provided a new data foundation for aircraft contrail detection. This study explored a detection algorithm for potential aircraft contrails using shortwave infrared hyperspectral images from the GF-5 AHSI. A spatial-spectral feature extraction method was proposed, which leveraged the complementary nature of spatial and spectral information in hyperspectral images. The method achieved an accuracy of over 97% and a false alarm rate of less than 2% on GF-5 hyperspectral image data. This work offers valuable insights for future research.

  • 1
• Bound States in the Continuum for Encoded Imaging

  HOU Shuai-Xing, YANG Si-Jia

  Abstract: (87) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Artificial structures known as metasurfaces are used extensively to control the propagation, phase, amplitude, and polarization of light by finely adjusting the characteristics of electromagnetic waves on a sub-wavelength scale. In this work, we suggest a Bound States in the Continuum (BIC) structure based on a metallic metasurface. We were able to achieve a notable BIC peak at a frequency of 0.8217 terahertz (THz) by carefully modifying the metallic structures utilizing CST and COMSOL tools.We discovered through multi-level expansion analysis that the electric dipole (ED) is primarily responsible for this structure's resonant characteristic. We created and put into operation an image system that operates at 0.8217 THz by utilizing the features of BIC. According to experimental data, the imaging system offers outstanding sensitivity and resolution, indicating great promise for terahertz imaging. In addition to offering fresh concepts for the creation of metasurface-based BIC structures, our research gives useful references for the advancement of high-performance terahertz imaging technologies.

  • 1
• Cavity-enhance absorption spectroscopy for the measurement of Oxygen concentration

  SONG Jun-Ling, RAO Wei, WANG Lin-Yan, ZHU Xiao-Hui, WANG Dian-Kai, FENG Gao-Ping

  Abstract: (25) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  A high-performance oxygen detection system enables real-time online monitoring of critical parameters such as oxygen concentration and flow velocity within the engine, ensuring optimal operational efficiency. In flow field tests for engines such as scramjet and aviation engines, the complex environment characterized by high temperatures, pressures, and velocities, along with limited measurement space, poses significant challenges for accurate flow field diagnostics. To address these challenges, a device for measuring oxygen component concentration based on cavity-enhanced absorption spectroscopy (CEAS) was developed. The device features an embedded optical probe design and incorporates multi-directional adjustment mechanisms at both the transmitting and receiving ends to facilitate precise optical path alignment, enhancing its applicability in engineering experiments. Experimental results demonstrated that, in a static environment, the measured oxygen concentration was 20.846?0.97%.. In shock tube experiments, the system successfully captured three distinct states: before the arrival of the incident shock wave, after the passage of the incident shock wave but before the reflected shock wave arrived, and after the passage of the reflected shock wave. The measured oxygen concentration data were consistent with theoretical predictions.

  • 1
• Silicon valley photonic crystal Mach-Zehnder thermo -optic modulator

  ZHANG Xin-Yan, LIN Han, FEI Hong-Ming

  Abstract: (39) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Thermo-optic modulators are key components of optical communication systems, and their performance directly affects system efficiency. With the development of silicon optothermonic technology, silicon thermo-optic modulators have been widely used in optothermonic chips. Conventional silicon optical modulators are large in size and have high losses. In recent years, researchers have proposed to use the slow light effect of photonic crystals to reduce the footprint of modulators. Related studies have shown that these devices have advantages, such as small size and low driving voltage. However, the optical transmittance of thermo-optic modulators based on photonic crystals is still affected by defects caused by fabrication errors. Valley photonic crystal optical waveguides can achieve scattering-immune high-efficiency unidirectional transmission, providing a new venue for realizing high-performance photonic devices. In this paper, a new silicon thermo-optic modulator based on a valley photonic crystal Mach-Zehnder interferometer (MZI) is designed. The electrical heating mechanism is introduced on one of the waveguides of the MZI. The thermo-optic effect modulates the refractive index to achieve precise phase modulation of the transmitted light. The thermo-optic modulator device has a small footprint of only 9.26 μm × 7.99 μm, which can achieve a high forward transmittance of 0.91, an insertion loss of 0.41 dB, and a modulation contrast of 11.75 dB. It can also be experimentally fabricated using complementary metal oxide semiconductor (CMOS) technology, so it will have broad application prospects. This modulation principle can be widely used in designing different thermo-optic modulation devices.

  • 1
• Study of Dual-Frequency-Band Millimeter-Wave Extended Interaction Klystron Based on Dual-2π Mode

  XU Che, LU Jia-Ni, TANG Yong-Liang, TANG Xian-Feng

  Abstract: (42) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  This paper proposes a novel dual-frequency-band millimeter-wave extended interaction klystron amplifier (EIKA). It is primarily based on the multimode operating mechanism of dual-2π mode. This design integrates a broadband traveling-standing-wave mode input cavity with a dual-2π standing-wave mode output cavity, resulting in a compact slow-wave structure design that efficiently operates within a total circuit length of approximately 24 mm. Particle-in-cell simulation results reveal that under a 15.6 kV, 1 A electron beam and a uniform 0.6 T magnetic field, the device achieves output power for 183-1024 W across a broadly 1.20 GHz bandwidth, spanning 93.76-94.96 GHz. Remarkably, it facilitates dual-band output in both lower-2π and upper-2π bands, delivering maximum gains of 37.09 dB (1024.10 W at 93.90 GHz) and 35.75 dB (752.20 W at 94.84 GHz), with -3 dB bandwidths of 0.33 GHz and 0.20 GHz, respectively. The effectiveness for the dual-2π mode design is further confirmed through a cold-test experiment using the perturbation method. This experiment demonstrated typical dual-2π mode field distribution profiles, affirming the design's efficacy.

  • 1
• Broadband high-extinction-ratio nonvolatile optical switch based on phase change material

  LIANG Kai, YUE Wen-Cheng, XU Fan, ZHU Qian-Nan, ZHANG Jian-Min, WANG Shu-Xiao, CAI Yan

  Abstract: (57) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  In this paper, we present a broadband, high-extinction-ratio, nonvolatile 2×2 Mach-Zehnder interferometer (MZI) optical switch based on the phase change material Sb2Se3. The insertion loss (IL) is 0.84 dB and the extinction ratio (ER) reaches 28.8 dB at the wavelength of 1550 nm. The 3 dB bandwidth is greater than 150 nm. Within the 3 dB bandwidth, the ER is greater than 20.3 dB and 16.3 dB at bar and cross states, respectively. The power consumption for crystallization and amorphization of Sb2Se3 is 105.86 nJ and 49 nJ, respectively. The switch holds significant promise for optical interconnects and optical computing applications.

  • 1
• Research progress of active metasurface for intelligent radar stealth

  WANG Dong-Shu, LIU Tong-Hao, WANG Liu-Ying, LIU Gu, CHENG Hai-Qing, CHENG Meng-Zhong, GE Chao-Qun, WANG Long, WANG Bing, XU Ke-Jun

  Abstract: (62) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The new active metasurface has the advantages of small size, light weight and easy integration, so it has an important application prospect in weapon radar intelligent stealth. Based on this, focusing on the requirements of radar intelligent stealth for current weapons and equipment, this paper expounds the methods, approaches and performance advantages of active metasurface in electromagnetic wave regulation, reviews the development history of various active metasurface, and summarizes the research status and future development direction of active metasurface for radar intelligent stealth. It provides the relevant theoretical basis and design reference for the wide application of active metasurface in intelligent stealth of weapon equipment radar.

  • 1
• Effect of Extrinsic resistances on Noise performance for Deep Submicron MOSFET

  GAO HANQI, Jin Jing, Zhou JianJun

  Abstract: (46) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  This paper investigates the impact of extrinsic resistances on the noise performance of deep submicron MOSFETs using the noise correlation matrix method. Analytical closed-form expressions for calculating the four noise parameters are derived based on the small-signal and noise-equivalent circuit models. The results show strong agreement between simulated and experimental data for MOSFETs with a gate length of 40 nm and dimensions of 4×5 μm (number of gate fingers × unit gate width).

  • 1
• Anisotropic Tetratellurium-Iridium-Nibium Terahertz Detector

  Liu Yuan, Yang Si-Jia, XU Yong-Jiang, SHEN Yun, DENG Xiao-Hua

  Abstract: (81) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Topological semimetal materials have garnered significant interest due to their distinctive electronic structures and unique properties. They serve as a foundation for exploring various physical phenomena, including the anomalous Hall effect, topological phase transitions, and negative magnetoresistance, while also offering potential solutions to the "THz Gap." This study focuses on the type-II Weyl semimetal tetratellurium iridium niobium (NbIrTe4) terahertz detector, which exhibits a responsivity of 4.36 A/W, a noise equivalent power of 12.34 pW/Hz1/2, and an anisotropic resistance ratio of 32 at room temperature. This research paves the way for achieving high-performance terahertz detection at room temperature and serves as a reference for investigating the Weyl semimetal.

  • 1
• Strongly Coupled Electro-optical Tunable 780 nm Ultra-Narrow Linewidth Laser Source

  Xue Kai, RONG Jia-Min, XING Guo-Hui, XUE Jun-Jie, LIU Wen-Yao, ZHOU Yan-Ru, XING En-Bo, TANG Jun, LIU Jun

  Abstract: (61) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Highly matched and precisely locked to the absorption lines of rubidium (Rb) atoms, 780 nm lasers play a crucial role in fields such as quantum computing, precision measurements, and high-sensitivity sensing, with clear requirements for strong coherence and fast tunability. In this paper, based on the self-injection locking and ultra-high quality factor Whispering gallery mode (WGM) cavity, a 780 nm narrow linewidth (23.8kHz) tunable laser with a single longitudinal mode output is verified. More importantly, benefiting from the optimized combined coupling coefficient K and via the lithium niobate electro-optic effect, the laser frequency detuning is effectively improved, with the experimental tuning range reaching 110 pm and the tuning efficiency of 6.4 pm/V. This work provides a high-performance design solution for fast-tunable narrow-linewidth lasers for applications in the near-infrared range, which is expected to play an essential role in the future.

  • 1
• The Investigation of Concentrated Triple-Junction Solar Cells Based on InGaAsP

  ZHANG Jicheng, GUAN Weiwei, SUN Qiangjian

  Abstract: (55) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  The InGaAsP material with an energy bandgap of 1.05 eV was grown on InP substrates by all-solid-state Molecular Beam Epitaxy (MBE) technique. The material had no mismatch dislocations between the substrate and the epitaxial layer, and also exhibited high interface quality and luminescent quality. Based on InGaAsP material, single-junction InGaAsP solar cells were grown on InP substrates, and GaInP/GaAs dual-junction solar cells were grown on GaAs substrates. These two separate cells were then bonded together using wafer bonding technology to fabricate a GaInP/GaAs/InGaAsP triple-junction solar cell. Under the AM1.5G solar simulator, the conversion efficiency of the GaInP/GaAs/InGaAsP wafer-bonded solar cell is 30.6%, achieving an efficiency of 34% under concentration. The results indicate that MBE can produce high-quality InGaAsP material, and room-temperature wafer bonding technology holds great potential for the fabrication of multi-junction solar cells.

  • 1
• Research on the Metrological Calibration Technology Scheme of Brightness Temperature for the Space-borne Microwave Radiometer Calibration Target

  GAO Qing-Song, LI De-Tian, TAO Yuan, YANG Lei, ZHANG Hu-Zhong, MA Dong-Tao, PENG Miao-Miao, JIN Ming, GUO Qiang, JIANG Shi-Chen, LI Yi-Nan, CHENG Chun-Yue, LI Xue

  Abstract: (71) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  This paper addresses the application requirements for the brightness temperature calibration of the hot calibration target for spaceborne microwave radiometers. Based on the temperature gradient characteristics of the absorbing coating of the calibration target and the mechanism of brightness temperature deviation, combined with practical temperature measurement methods and experimental means, a brightness temperature metrological calibration technology solution applicable for in-orbit use is studied. Given the current background of high emissivity design and determination technology of the calibration target being basically perfected, the paper focuses on summarizing the methods for determining the temperature gradient characteristics of the calibration target coating. The goal is to construct an in-orbit available brightness temperature calibration method that uses multiple parameters, such as the temperature measurements of the metal inner cone of the calibration target and the temperature measurements near the radiation aperture of the calibration target. Based on feasible electromagnetic simulation technology, thermal simulation technology, platinum resistance and infrared temperature measurement techniques, the paper preliminarily summarizes the implementation path of the brightness temperature calibration technology system for spaceborne calibration targets. This involves first constructing a basic brightness temperature calibration model considering uniform background brightness temperature and improving the mapping relationship from the inner cone temperature of the calibration target and the equivalent background brightness temperature to the longitudinal temperature gradient of the coating. Subsequently, an application model for brightness temperature calibration considering the installation environment is constructed, improving the mapping relationship from the temperature measurements of the inner cone and the radiation aperture area of the calibration target to the brightness temperature deviation of the calibration target. Finally, the validation and application of the brightness temperature calibration model are discussed.This work serves as an important technical basis and reference for further improving the accuracy of the calibration target's brightness temperature and even developing space microwave radiometric measurement benchmarks.

  • 1
• Review on infrared polarization image fusion methods

  zhengjinjiang, LI Xiao-Xia, ZHAO Da-Peng, CHEN Yi, WU Meng-Xing

  Abstract: (92) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Infrared polarization image fusion can fully utilize the polarization information of the scene, compensate for the disadvantage of infrared intensity images in describing high-frequency information such as scene contour edges and texture details, and has unique advantages in target detection and recognition, background noise suppression, and counter camouflage. The article summarized the research progress of infrared polarization image fusion technology from two aspects: single algorithm image fusion and multi-algorithm combination image fusion. It analyzed the design ideas of typical algorithms and summarized the advantages and disadvantages of each algorithm. Based on the current trend where single algorithm serves as the mainstream and multi-algorithm combination as the development trend for infrared polarization image fusion, this paper anticipates its potential future development direction.

  • 1
• Lightweight Remote Sensing Multimodal Large Language Model Based on Knowledge Distillation

  ZHANG Xin-Yue, FENG Shi-Yang, WANG Bin

  Abstract: (218) HTML (0) PDF (0.00 ByteKB) (0)

  Abstract:

  Remote sensing multimodal large language models (MLLMs), which integrate rich visual-linguistic modal information, have shown great potential in areas such as remote sensing image analysis and interpretation. However, existing knowledge distillation methods primarily focus on the compression of unimodal large language models, neglecting the alignment of features across modalities, thus hindering the performance of large language models in cross-modal tasks. To address this issue, a lightweighting method for remote sensing MLLMs based on knowledge distillation is proposed. This method achieves effective alignment of multimodal information by aligning the outputs across modalities at the feature level. By introducing the reverse Kullback-Leibler divergence as the loss function and combining optimization strategies such as teacher mixed sampling and single-step decomposition, the generalization and stability of the student model are further enhanced. Experimental results demonstrate that the proposed method achieves higher accuracy and efficiency in four downstream tasks of remote sensing image scene classification, visual question answering, visual localization, and image description, significantly reducing the number of model parameters and the demand for computational resources, thereby providing a new solution for the efficient application of MLLMs in the field of remote sensing.

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Volume 44,2025 Issue 2

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

  Abstract

  2002,21(3):161-166

  Abstract: (2515) HTML (123) PDF (392.26 KKB)(89900)

  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.

• 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

  Abstract: (1058) HTML (132) PDF (396.69 KKB)(62114)

  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。

• 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

  Abstract: (1741) HTML (139) PDF (262.82 KKB)(54358)

  Abstract:

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

• OPTICAL SPECTRA OF LOW-DIMENSIONAL SEMICONDUCTORS

  FuY ChiragwandiZ GoethbergP WillanderM

  2003,22(6):401-405

  Abstract: (1081) HTML (128) PDF (483.11 KKB)(29645)

  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.

• 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

  Abstract: (7826) HTML (465) PDF (411.06 KKB)(22286)

  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。

• 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

  Abstract: (1467) HTML (94) PDF (450.58 KKB)(16724)

  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.

Infrared Spectroscopy and Remote Sensing Technology

• 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

  Abstract: (10637) HTML (415) PDF (221.64 KKB)(16299)

  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

  Abstract: (7415) HTML (402) PDF (271.63 KKB)(15847)

  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.

Infrared Physics, 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: (3617) HTML (215) PDF (4.42 MKB)(15527)

  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.

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: (3991) HTML (239) PDF (5.05 MKB)(14199)

  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%.

• HYPERSPECTRAL REMOTE SENSING IMAGE CLASSIFICATION BASED ON SUPPORT VECTOR MACHINE

  TAN Kun, DU Pei-Jun

  2008,27(2):123-128

  Abstract: (3071) HTML (936) PDF (735.00 KKB)(13814)

  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 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

  Abstract: (1337) HTML (111) PDF (196.71 KKB)(13457)

  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.

Interdisciplinary Research on Infrared Science

• IMAGE SEGMENTATION BY SPECTRAL CLUSTERING ALGORITHM WITH SPATIAL COHERENCE CONSTRAINTS

  JIA Jian-Hua, JIAO Li-Cheng

  2010,29(1):69-74

  Abstract: (11566) HTML (387) PDF (808.83 KKB)(13249)

  Abstract:

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

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

  ZHOU Yue, MAO Xiao-Nan

  2010,29(1):63-68

  Abstract: (11446) HTML (439) PDF (750.21 KKB)(13061)

  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.

• 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

  Abstract: (986) HTML (103) PDF (331.55 KKB)(12806)

  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.

40th Years

• Recent hotspots and innovative trends of infrared photon detectors

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

  2022,41(1):15-39 ,DOI: 10.11972/j.issn.1001-9014.2022.01.001

  Abstract: (3445) HTML (3736) PDF (7.46 MKB)(12571)

  Abstract:

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

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• SURFACE COMPONENT CHANGE OF Hg0.8Cd0.2Te INDUCED BY HIGH POWER PULSED TEA-CO2 LASER

  CAI Hu, CHENG Zu-Hai, ZHU Hai-Hong, ZUO Du-Luo

  2006,25(3):165-169

  Abstract: (1031) HTML (109) PDF (434.30 KKB)(12329)

  Abstract:

  利用场发射扫描电子显微镜对TEA-CO2强激光脉冲辐照的Hg0.8Cd0.2Te晶片表面进行了观察,并利用电镜自带的能谱分析仪对其表面进行了成分分析.在单脉冲能量为1.91J,峰值功率密度为2.63×107W/cm2的脉冲CO2激光辐照下,晶片表面呈现出熔融迹象,且晶片表面的化学组分比发生明显的变化.理论与实验研究结果表明激光急速加热使晶体表面的Hg-Te键破坏,从而导致Hg损失,而Hg损失程度与热作用过程的时间有关.随着脉冲作用次数的增加,多脉冲的连续作用使Hg损失加剧,晶片表面成分变化更加突出.

• IMAGE RETRIEVAL BASED ON IMAGE ENTROPY AND SPATIAL DISTRIBUTION ENTROPY

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

  2005,24(2):135-139

  Abstract: (1510) HTML (99) PDF (380.01 KKB)(12246)

  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

  Abstract: (11864) HTML (435) PDF (1.12 MKB)(12149)

  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.