2024

• Record 13 of
  
  Title:Scalable parallel ultrafast optical random bit generation based on a single chaotic microcomb
  
  Author(s):Li, Pu(1,2,3); Li, Qizhi(4); Tang, Wenye(4); Wang, Weiqiang(5); Zhang, Wenfu(5); Little, Brent E.(5); Chu, Sai Tek(6); Shore, K. Alan(7); Qin, Yuwen(1,2,3); Wang, Yuncai(1,2,3)
  Source: Light: Science and Applications  Volume: 13  Issue: 1  DOI: 10.1038/s41377-024-01411-7  Published: December 2024  
  Abstract:Random bit generators are critical for information security, cryptography, stochastic modeling, and simulations. Speed and scalability are key challenges faced by current physical random bit generation. Herein, we propose a massively parallel scheme for ultrafast random bit generation towards rates of order 100 terabit per second based on a single micro-ring resonator. A modulation-instability-driven chaotic comb in a micro-ring resonator enables the simultaneous generation of hundreds of independent and unbiased random bit streams. A proof-of-concept experiment demonstrates that using our method, random bit streams beyond 2 terabit per second can be successfully generated with only 7 comb lines. This bit rate can be easily enhanced by further increasing the number of comb lines used. Our approach provides a chip-scale solution to random bit generation for secure communication and high-performance computation, and offers superhigh speed and large scalability. © The Author(s) 2024.
  Accession Number: 20241015704601
• Record 14 of
  
  Title:Polarization-Based Enhancement for Oceanic Constituents and Inherent Optical Properties (Iops) Retrieval from Multi-Angular Polarimetric Measurements Over Global Oceans
  
  Author(s):Liu, Jia(1,2,3,4); Li, Chunxia(5); He, Xianqiang(3); Chen, Tieqiao(2); Jia, Xinyin(2); Bai, Yan(3); Liu, Dong(6); Liu, Yupeng(1); Yang, Wentao(7); Wang, Yihao(2); Zhang, Geng(2); Li, Siyuan(2); Hu, Bingliang(2); Pan, Delu(3)
  Source: SSRN  Volume:   Issue:   DOI: 10.2139/ssrn.4803997  Published: April 23, 2024  
  Abstract:Multi-angle polarization characteristics of water-leaving radiation, which contain rich information on oceanic constituents and inherent optical properties (IOPs), have often been neglected. In this study, global radiative transfer (RT) simulations for the polarization characteristics of water-leaving radiance (Lw) were performed using the vector radiative transfer model for a coupled ocean-atmosphere system (PCOART). And, a global polarization-based algorithm for retrieving oceanic constituents and inherent optical properties (IOPs) was developed, employing the Fully Connected U-Net (FCUN). The retrieval performance of the algorithm was then analyzed using in-situ measurements collected during the Qiandao Lake field campaign. Results indicated that the low degrees of polarization (DOP) at short blue bands at solar zenith angle of 0° predominantly occurred in the tropical and subtropical oceans, with the lowest DOP value of 0.0176 observed in the extra oligotrophic subtropical gyres. The global mean absolute percentage error (MAPE) of the FCUN predictions compared to RT simulations for oceanic constituents (Chla, ag(443), NAP) and IOPs (a, b, aph, bph, aNAP, bNAP, bb, bbph, bbNAP) at 443 nm were 6.24%, 3.90%, 10.65%, 2.85%, 3.15%, 3.79%, 4.42%, 3.90%, 3.90%, 3.13%, 4.44%, and 3.90%, respectively, with mean global MAPE values of 4.52%. Additionally, the FCUN model’s predictions were consistent with RT simulation inputs under various random instrument noise conditions, with mean global MAPE values of 6.74% and 8.84% for those 12 retrieved parameters, respectively. Moreover, the retrieval performance analysis of FCUN on the in-situ measurements was performed with MAPE for Chla, a, aph, bb at 443 nm of 31.80%, 29.65%, 34.87%, and 43.04%, respectively. The importance of multi-angles polarization observations of Lw for ocean constituents and IOPs retrieval were also examined with the global mean MAPE decreasing from 16.91% to 1.48% as the observation angles increasing. Overall, the global polarization-based inversion model exhibited substantial potential for the oceanic constituents and IOPs retrieval of using multi-angle polarimetry. © 2024, The Authors. All rights reserved.
  Accession Number: 20240169237
• Record 15 of
  
  Title:Space advanced technology demonstration satellite
  
  Author(s):Zhang, XiaoFeng(1); Chen, Wen(1); Zhu, XiaoCheng(1); Meng, Na(1); He, JunWang(1); Bi, XingZi(1); Zhang, YongHe(1); Shi, Qi(1); Li, Fei(1); Liu, Rui(1); Feng, ZhengGong(1); Liu, Liu(1); Li, JinSong(1); Wu, HaiChen(1); Xu, DongXiao(1); Li, TaiJie(1); Huang, JiangJiang(1); Liu, Shuo(1); Li, TianTong(1); Yu, XianSheng(1); Gao, Yang(1); Zhou, Heng(1); Ban, HanYu(1); Zhang, YanLi(1); Zhang, YueTing(1); Yang, YingQuan(1); He, Tao(1); Duan, XuLiang(1); Chen, Xin(1); Wang, YaMin(1); Sun, AnTai(1); Zhang, KuoXiang(1); Sun, Ying(1); Wang, YaoBin(1); Fan, ChengCheng(1); Xiong, ShaoLin(2); Li, XinQiao(2); Wen, XiangYang(2); Ling, ZhiXing(3); Sun, XiaoJin(4); Zhang, Chen(3); Bai, XianYong(3); Wang, ZhanShan(5); Deng, YuanYong(3); Tian, Hui(6); Yang, JianFeng(7); Xue, HongBo(8); Sang, Peng(8); Liu, JinGuo(9); Zheng, HuiLong(10); Zhu, Xiang(8); He, JianWu(11); Li, Hui(12); Xu, LuXiang(13); Xu, ShuYan(14); Chen, WenWu(15); Liu, ZhenDong(15); Wang, ZhaoLi(16); Mao, XiangLong(7); Gao, Rong(7); Li, ZongXuan(17); Ding, GuoPeng(1); Wang, XinYu(1); Dou, RunJiang(18); Weng, LuBin(19); Luo, Hao(20); Wang, YaPing(1); Liang, XianFeng(8); Fang, ZiRuo(1)
  Source: Science China Technological Sciences  Volume: 67  Issue: 1  DOI: 10.1007/s11431-023-2510-x  Published: January 2024  
  Abstract:The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of ∼500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance. © 2023, Science China Press.
  Accession Number: 20240115304467
• Record 16 of
  
  Title:Multilevel-based algorithm for hyperspectral image interpretation
  
  Author(s):Qiu, Shi(1); Ye, Huping(2,3); Liao, Xiaohan(2,3,4); Zhang, Benyue(1); Zhang, Miao(1); Zeng, Zimu(1)
  Source: Computers and Electrical Engineering  Volume: 113  Issue:   DOI: 10.1016/j.compeleceng.2023.109033  Published: January 2024  
  Abstract:Hyperspectral imagery contains spatial and spectral information, which can reveal the material properties of the target while intuitively displaying its spatial attributes. It has been applied in target recognition, search and rescue, and other fields. However, manual detection inevitably leads to missed detections and false alarms, necessitating the assistance of artificial intelligence for detection. To address this, we propose the multilevel-based algorithm for hyperspectral image interpretation. 1) From the spatial and spectral dimensions, we propose a semantic segmentation algorithm based on multidimensional information fusion to achieve semantic segmentation. 2) From the semantic and textual representation dimensions, we introduce a context interpretation module based on visual attention. We construct both real and simulated databases to validate the effectiveness of the algorithm. Experimental results demonstrate that the average accuracy of semantic segmentation achieved by the proposed algorithm is 74.3%. Additionally, the BLEU1 score reaches 71.2, outperforming mainstream algorithms by 1.4. © 2023 Elsevier Ltd
  Accession Number: 20234915147747
• Record 17 of
  
  Title:Generation of subcycle isolated attosecond pulses by pumping ionizing gating
  
  Author(s):Wu, Zhaohui(1); Zeng, Xiaoming(1); Li, Zhaoli(1); Zhang, Zhimeng(1); Wang, Xiaodong(1); Wang, Xiao(1); Mu, Jie(1); Zuo, Yanlei(1); Su, Jingqin(1); Peng, Hao(2); Cao, Huabao(3); Fu, Yuxi(3); Riconda, C.(4); Weber, S.(5)
  Source: Physical Review Research  Volume: 6  Issue: 1  DOI: 10.1103/PhysRevResearch.6.013126  Published: January 2024  
  Abstract:We present an interesting approach named as pumping ionizing gating (PIG) for the generation of isolated attosecond pulses (IAPs). In this regime, a short laser is used to ionize a preexisting gas grating, creating a fast-extending plasma grating (FEPG) having an ionization front propagating with the velocity of light. A low-intensity long counterpropagating pump pulse is then reflected by a very narrow region of the ionization front, only where the Bragg conditions for resonant reflection is satisfied. Consequently, the pump reflection is confined within a subcycle region called PIG, and forms a wide-band coherent IAP in combination with the frequency up-conversion effect due to the plasma gradient. This approach results in a new scheme to generate IAPs from long picosecond pump pulses. Three-dimensional (3D) simulations show that a 1.6 ps, 1 μm pump pulse can be used to generate a 330 as laser pulse with a peak intensity approximately 33 times that of the pump and a conversion efficiency of around 0.1%. These results highlight the potential of the PIG method for generating IAPs with high conversion efficiency and peak intensity. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
  Accession Number: 20240615527419
• Record 18 of
  
  Title:All-polarization-maintaining mode-locked Holmium-doped fiber laser based upon nonlinear polarization evolution
  
  Author(s):Tu, Lisha(1,2); Tang, Ziya(1); Li, Keyi(1); Wang, Jiachen(1); Lin, Hua(3); Zhang, Wenfei(1); Lue, Qitao(4); Guo, Chunyu(1); Ruan, Shuangchen(2)
  Source: Infrared Physics and Technology  Volume: 136  Issue:   DOI: 10.1016/j.infrared.2023.105054  Published: January 2024  
  Abstract:An all-polarization-maintaining, all-fiberized holmium (Ho) doped fiber laser mode-locked by nonlinear polarization evolution (NPE) is experimentally demonstrated for the first time. The NPE mechanism is realized via the combination of a polarizer and the cross-fusion of three sections of polarization maintaining (PM) fibers. With the appropriate manipulation of the splicing angles between the birefringent axes of the PM fibers, a highly stable mode locked operation is realized. The laser delivers stable dissipative-soliton resonance (DSR) pulses with a repetition rate of 10.34 MHz and an average power of 223.95 mW, corresponding to a pulse energy of 21.64 nJ and a peak power of 11 W. Furthermore, the output power test over 2 h implies superior stability of this design. The oscillator, performing the characteristics of self-starting, high pulse energy, and good stability, is attractive and promising for various practical application. © 2023
  Accession Number: 20240115320784
• Record 19 of
  
  Title:Observation of the colliding process of plasma jets in the double-cone ignition scheme using an x-ray streak camera
  
  Author(s):Liu, Zhengdong(1,2); Wu, Fuyuan(3,4); Zhang, Yapeng(1,2); Yuan, Xiaohui(3,4); Zhang, Zhe(4,5,6); Xu, Xiangyan(7); Xue, Yanhua(7); Tian, Jinshou(7); Zhong, Jiayong(1,2,4); Zhang, Jie(3,4,5)
  Source: Physics of Plasmas  Volume: 31  Issue: 4  DOI: 10.1063/5.0188056  Published: April 1, 2024  
  Abstract:The double-cone ignition scheme is a novel approach with the potential to achieve a high gain fusion with a relatively smaller drive laser energy. To optimize the colliding process of the plasma jets formed by the CHCl/CD shells embedded in the gold cones, an x-ray streak camera was used to capture the spontaneous x-ray emission from the CHCl and CD plasma jets. High-density plasma jets with a velocity of 220 ± 25 km/s are observed to collide and stagnate, forming an isochoric plasma with sharp ends. During the head-on colliding process, the self-emission intensity nonlinearly increases because of the rapid increase in the density and temperature of the plasma jets. The CD colliding plasma exhibited stronger self-emission due to its faster implosion process. These experimental findings effectively agree with the two-dimensional fluid simulations. © 2024 Author(s).
  Accession Number: 20241916063677
• Record 20 of
  
  Title:Room-temperature MoTe2/InSb heterostructure large-area terahertz detector
  
  Author(s):Wang, Jiatong(1); Zhang, Min(1,3); Zhou, Zhiwen(1); Li, Ling(1); Song, Qi(2); Yan, Peiguang(1)
  Source: Infrared Physics and Technology  Volume: 137  Issue:   DOI: 10.1016/j.infrared.2024.105190  Published: March 2024  
  Abstract:As a building block for terahertz system, terahertz detector is expected to achieve high-performance, room-temperature, low-cost and large-area detection available. However, the state-of-the-art technologies still suffer from various drawbacks. This paper presents a MoTe2/InSb heterostructure large-area terahertz detector. With the photoactive region of heterostructure, carriers are allowed to assemble within the interface due to the carrier mobility difference, resulting in detection sensitivity improvement. The structures and bonding of MoTe2/InSb heterostructure were characterized by Raman spectroscopy. Besides, large-scale interdigital electrodes with subwavelength spacing are employed at the bottom of photoactive region, which contrasts with normal electrodes coated on both sides of the active layer, endowing a large effective detection area of 2 mm × 6.65 mm with the detector. Subwavelength electrodes spacing not only facilitates the directional migration of carriers, but also induces electromagnetic induced well (EIW) effects to obtain extraordinary performance. As a result, the detector achieves a noise equivalent power (NEP) of 2.66 pW Hz-1/2 and a detectivity (D*) of 0.53 × 1012 cm Hz1/2 W−1 under 0.1 THz radiation at room temperature. The proposed high-performance terahertz detector exhibits remarkable prospects in varieties of applications. © 2024 The Author(s)
  Accession Number: 20240615520725
• Record 21 of
  
  Title:Compressed Spectrum Reconstruction Method Based on Coding Feature Vector Enhancement
  
  Author(s):Cao, Chipeng(1,2); Li, Jie(3); Wang, Pan(1); Qi, Chun(3)
  Source: IEEE Transactions on Geoscience and Remote Sensing  Volume: 62  Issue:   DOI: 10.1109/TGRS.2023.3347220  Published: 2024  
  Abstract:Compressive spectral imaging (CSI) is a snapshot spectral imaging technique that rapidly captures the spectral information of a target in a single exposure and effectively reconstructs high spectral data using reconstruction algorithms. However, due to the presence of a large number of identical pixels in the measured image, which map to different prior spectral information, existing algorithms struggle to establish an accurate pixel separation representation model. To improve the separation effect between pixels and enhance the representation capability of the measured image pixels, we propose a compressed spectral reconstruction method with enhanced encoding feature vectors. By designing encoding information calculation rules based on a combination of linear and nonlinear functions, encoding features are calculated according to the spatial coordinate position information and wavelength information of the pixels, effectively enhancing the separation representation characteristics between channels and neighboring pixels through the addition of encoding features. Furthermore, by utilizing the semantic similarity between the predicted results of the prior model and the prior spectral image, the reconstruction problem is transformed into a total variation (TV) minimization problem between the predicted results of the prior model and the reconstruction results, combined with the alternating direction method of multipliers (ADMMs) to achieve accurate pixel reconstruction. The experimental setup utilizes a dual-camera compressed spectral imaging (DCCHI) system, consisting of a dual-dispersion coded aperture compressed spectral imaging (DD-CASSI) system and a grayscale imaging system. Various experiments have shown that the proposed method outperforms in reconstructing quality and displays superior algorithmic performance. © 1980-2012 IEEE.
  Accession Number: 20240215337320
• Record 22 of
  
  Title:Hybrid Grid Pattern Star Identification Algorithm Based on Multi-Calibration Star Verification
  
  Author(s):Shen, Chao(1); Ma, Caiwen(1); Gao, Wei(1); Wang, Yuanbo(1)
  Source: Sensors  Volume: 24  Issue: 5  DOI: 10.3390/s24051661  Published: March 2024  
  Abstract:In order to solve the star identification problem in the lost space mode for scientific cameras with small fields of view and higher instruction magnitudes, this paper proposes a star identification algorithm based on a hybrid grid pattern. The application of a hybrid pattern generated by multi-calibration stars in the initial matching enables the position distribution features of neighboring stars around the main star to be more comprehensively described and avoids the interference of position noise and magnitude noise as much as possible. Moreover, calibration star filtering is adopted to eliminate incorrect candidates and pick the true matched navigation star from candidate stars in the initial match. Then, the reference star image is utilized to efficiently verify and determine the final identification results of the algorithm via the nearest principle. The performance of the proposed algorithm in simulation experiments shows that, when the position noise is 2 pixels, the identification rate of the algorithm is 96.43%, which is higher than that of the optimized grid algorithm by 2.21% and the grid algorithm by 4.05%; when the magnitude noise is 0.3 mag, the star identification rate of the algorithm is 96.45%, which is superior to the optimized grid algorithm by 2.03% and to the grid algorithm by 3.82%. In addition, in the actual star image test, star magnitude values of ≤12 mag can be successfully identified using the proposed algorithm. © 2024 by the authors.
  Accession Number: 20241115750356
• Record 23 of
  
  Title:Motion detection of swirling multiphase flow in annular space based on electrical capacitance tomography
  
  Author(s):Zhao, Qing(1); Liao, Jiawen(1); Chen, Weining(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 13090  Issue:   DOI: 10.1117/12.3026097  Published: 2024  
  Abstract:Cyclone multiphase flow in the annular space is widely used in fluid machinery, such as burner and pneumatic conveying. However, the annular flow field is complex, and the related research is not sufficient. To improve the safety and efficiency of equipment, this paper proposes a method for detecting the motion state of swirling fluid in annular space by integrating computational fluid dynamics (CFD) and electrical capacitance tomography (ECT), calculates the motion characteristics of swirling multiphase flow in the annular space using the CFD, and visually measures the distribution and motion state of swirling multiphase flow in the annular space using the ECT. Numerical simulation and experimental results show that the results of the two methods are in good agreement, indicating that the model selected in this paper in the CFD is correct. The CFD effectively reveals the distribution of swirling multiphase flow in the annular pipe, and the ECT can accurately reconstruct the position and size of swirling multiphase flow in the annular space. The combination of these two methods provides a new idea for the study of multiphase flow in annular space. © 2024 SPIE.
  Accession Number: 20241815993004
• Record 24 of
  
  Title:An optimization method for aircraft attitude measurement based on contour matching
  
  Author(s):Qin, Ruijiao(1,2); Tang, Huijun(3)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12978  Issue:   DOI: 10.1117/12.3019432  Published: 2024  
  Abstract:The pose information of aircraft is an important index to study flight status and aircraft performance[1]. This article mainly focuses on the research of aircraft attitude estimation based on contour matching, intending to achieve pose estimation of non-contact long-distance moving objects under the rigorous formula system of photogrammetry. The rationality of the algorithm proposed in this article has been proven through the analysis of experimental results. © 2024 COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20240615524021