激光通信地面测试终端间隔离度的仿真分析  

Simulation analysis of isolation between laser communication ground test equipments

作　　者：赵猛 颜昌翔[1,3] 吴从均 ZHAO Meng;YAN Chang-xiang;WU Cong-jun(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China;Center of Materials Science and Optoelectrics Engineering,University of Chinese Academy of Science,Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049 [3]中国科学院大学材料与光电研究中心,北京100049

出　　处：《中国光学》2020年第3期472-481,共10页Chinese Optics

基　　金：国家自然科学基金项目(No.61805235)。

摘　　要：受空间所限,激光通信地面测试平台与被测终端之间的距离远小于实际通信距离,导致测试平台光机等器件产生的后向散射杂光进入被测终端,从而严重影响被测终端的测试性能。从被测终端与测试平台间的光学干扰问题出发,本文研究了被测终端与测试平台间隔离度的关系,分别设计了卡塞格林和离轴三反光学天线,并根据杂散光传输模型,采用杂散光分析软件分析了光学天线结构形式及表面粗糙度两方面对隔离度的影响。分析结果表明,采用离轴三反光学天线时的隔离度明显高于卡塞格林光学天线,且隔离度随着光学表面粗糙度的减小而增大,当光学表面的粗糙度达到0.892 nm时,隔离度可达-86.22 dB。最后,推导了ABg模型与Harvey模型参数间的关系,并根据粗糙度与TIS计算公式,得出粗糙度分别为0.7 nm及0.5 nm的ABg模型参数,它们的终端间隔离度分别为-94.39 dB和-97.3 dB,实现了-90 dB的隔离度指标。The distance between a laser communication ground test platform and the terminal under test is far less than the actual communication distance due to space limitations.As a result,the backscattered stray light generated by the test platform optical device will enter the terminal under test,and the signal will seriously affect the performance of the terminal under test.Aiming at this problem,we research the isolation relation-ship between the tested terminal and the test platform based on the optical interference problem.The Cas-segrain and off-axis three-mirror optical antenna are designed respectively.According to astigmatic transmission model,the stray light analysis software is employed to analyze the influence of optical antenna's structure and surface roughness on the isolation.The results of the analysis show that the isolation when applying the off-axis three-mirror optical antenna is significantly higher than that applying the Cassegrain optical antenna,and that this isolation increases with a decrease in the roughness of the optical surface.When the optical surface's roughness reaches 0.892 nm,the isolation is−86.22 dB.Finally,the relationship between the ABg model and the Harvey model parameters is derived.According to calculation formula of the roughness and TIS,the ABg model parameters with roughness of 0.7 nm and 0.5 nm are theoretically obtained.The isolation between the terminals is−94.39 dB and−97.3 dB,achieving an isolation rating of−90 dB.

关 键 词：激光通信 光学天线 隔离度 表面散射模型 杂散光 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]