Author Affiliations
Abstract
1 Aerospace Laser Technology and Systems Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3 Shanghai Typhoon Institute, China Meteorological Administration, Shanghai 200030, China
A method of spectrum estimation based on the genetic simulated annealing (GSA) algorithm is proposed, which is applied to retrieve the three-dimensional wind field of typhoon Nangka observed by our research group. Compared to the genetic algorithm (GA), the GSA algorithm not only extends the detection range and guarantees the accuracy of retrieval results but also demonstrates a faster retrieval speed. Experimental results indicate that both the GA and GSA algorithms can enhance the detection range by 35% more than the least squares method. However, the convergence speed of the GSA algorithm is 17 times faster than that of the GA, which is more beneficial for real-time data processing.
coherent Doppler lidar three-dimensional wind field retrieval genetic simulated annealing algorithm spectrum estimation typhoon Chinese Optics Letters
2024, 22(4): 040101
Author Affiliations
Abstract
1 School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China
2 School of Science, Northeast Electric Power University, Jilin 132012, China
The emergent two-dimensional (2D) material, tin diselenide (SnSe2), has garnered significant consideration for its potential in image capturing systems, optical communication, and optoelectronic memory. Nevertheless, SnSe2-based photodetection faces obstacles, including slow response speed and low normalized detectivity. In this work, photodetectors based on SnS/SnSe2 and SnSe/SnSe2 p?n heterostructures have been implemented through a polydimethylsiloxane (PDMS)?assisted transfer method. These photodetectors demonstrate broad-spectrum photoresponse within the 405 to 850 nm wavelength range. The photodetector based on the SnS/SnSe2 heterostructure exhibits a significant responsivity of 4.99 × 103 A?W?1, normalized detectivity of 5.80 × 1012 cm?Hz1/2?W?1, and fast response time of 3.13 ms, respectively, owing to the built-in electric field. Meanwhile, the highest values of responsivity, normalized detectivity, and response time for the photodetector based on the SnSe/SnSe2 heterostructure are 5.91 × 103 A?W?1, 7.03 × 1012 cm?Hz1/2?W?1, and 4.74 ms, respectively. And their photodetection performances transcend those of photodetectors based on individual SnSe2, SnS, SnSe, and other commonly used 2D materials. Our work has demonstrated an effective strategy to improve the performance of SnSe2-based photodetectors and paves the way for their future commercialization.
two-dimensional materials tin diselenide heterostructures broad-spectrum photodetectors Journal of Semiconductors
2024, 45(3): 032703
Author Affiliations
Abstract
1 National Engineering Research Center for Optoelectronic Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
2 College of Materials Sciences and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calculated using the 2D finite difference time domain (FDTD) algorithm and the scattering matrix method (SMM). The periods and etch depth of the grating parameters have been optimized. A board area laser diode (BA-LD) with high-order diffraction gratings has been designed and fabricated. At output powers up to 10.5 W, the measured spectral width of full width at half maximum (FWHM) is less than 0.5 nm. The results demonstrate that the designed high-order surface gratings can effectively narrow the spectral width of multimode semiconductor lasers at high output power.
laser diodes distributed Bragg reflector high order gratings high power laser diodes narrow spectrum width Journal of Semiconductors
2024, 45(3): 032401
强激光与粒子束
2024, 36(4): 043020
强激光与粒子束
2024, 36(4): 043005
空军工程大学信息与导航学院通信系统教研室,陕西 西安 710077
卫星弹性光网络(SEON)具有容量大、抗干扰能力强和资源管控灵活等优点,是卫星互联网重要的发展方向。路由和频谱分配(RSA)问题是SEON的核心关键问题之一,针对SEON中的RSA问题,提出了一种基于路径状态感知的动态路由和频谱分配算法(PIV-SSA),PIV-SSA算法由分段频谱分配(SSA)算法和基于路径影响值的路由选择(PIV)算法组成,在SSA算法中,根据业务所需要的传输速率来分配不同位置的频谱资源,在PIV算法中,基于SSA算法预分配频谱结果,综合考虑频谱资源消耗、链路频谱状态和路径存活时间等因素来选择最佳传输路径。仿真实验结果表明,在不同负载强度下,相较于经典的KSP-FF算法,PIV-SSA算法在网络阻塞率上平均降低了4.60%以及在网络频谱利用率上平均提高了4.78%。
卫星互联网 卫星弹性光网络 路由和频谱分配 分段频谱分配 路径影响值 激光与光电子学进展
2024, 61(7): 0706014
1 中国科学技术大学光学与光学工程系,安徽 合肥 230026
2 中国科学院上海光学精密机械研究所航天激光工程部,上海 201800
3 中国科学院上海光学精密机械研究所空间激光传输与探测技术重点实验室,上海 201800
4 上海卫星互联网研究院有限公司,上海 200120
5 上海市卫星互联网重点实验室,上海 200120
在深空探测中,以微波为载体的通信、测距载荷面临链路损耗大、频谱资源紧张等问题。相比微波,激光光束发散角小,能量更为集中,可达更远的传输距离,以激光为载体的通信、测距载荷具有体积小、质量轻等优势。搭建了一套激光相干外差扩频通信测距一体化深空探测系统,提出了一种基于曲线模型的插值重采样方法,并对该曲线模型进行了理论仿真和实验验证。该模型由系统先验信息构建,是伪随机码相位差的线性函数。实验结果表明,对于静态目标,测距偏差不超过0.55 mm,测距精度不超过0.42 mm。对于动态目标,测距偏差不超过0.59 mm。静态和动态目标测距中实现了零误码通信。此外,扩频通信测距一体化设计应用于深空导航和深空时频同步,可以提高实时性。
扩频通信 插值重采样 通信测距一体化 深空探测 激光与光电子学进展
2024, 61(7): 0706010
63891部队光电对抗测试评估技术重点实验室,河南 洛阳 471000
超连续谱激光辐照可见光成像系统的干扰效应研究具有广泛的应用前景。针对超连续谱激光干扰效应,开展了不同辐亮度背景下超连续谱激光对可见光成像系统的干扰实验研究。采用白光光纤激光器产生超连续谱干扰源,搭建了超连续谱激光对可见光成像系统的干扰实验系统,得到不同辐亮度下探测器的干扰阈值数据,建立了探测器饱和像元数与干扰激光功率密度之间的数学关系模型,并对干扰阈值数据进行分析。结果表明,探测器饱和像元数与干扰激光功率密度近似呈线性对数关系,在低辐亮度背景下可见光成像系统更易受到干扰。实验结果对超连续谱激光干扰装备的设计、论证及作战使用具有一定的参考意义。
超连续谱激光 成像系统 干扰 不同辐亮度背景 饱和像元个数 激光与光电子学进展
2024, 61(8): 0811009