摘要
空间光通信中,需要通信双方检测入射光轴偏差以保证通信链路畅通。但光学天线控制系统使用的信标光经长距离传输后损耗过大,受背景光和暗电流噪声强烈干扰,系统中的四象限探测器(QD)对光斑位置检测精度下降。为解决这一问题,根据QD工作特性和噪声特性,提出了一种基于幅度调制和循环互相关运算的检测方法。该方法在QD输出信噪比(SNR)过低的情况下,可精确测量QD各象限输出的电流幅度,并以此计算出准确的光斑位置。实验结果表明:当QD的输出SNR为﹣14.58 dB时,该方法的绝对误差小于0.012 mm,证明了该方法的有效性。
In space optical communication,both communication terminals need to detect the deviation of the incident optical axis to ensure that the communication link is unblocked.However,the beacon light used by the optical antenna control system has a large loss after long-distance transmission,and is strongly disturbed by background light and dark current noise.So,the accuracy of spot detection of the four-quadrant detector(QD)is reduced.To solve this problem,according to QD operating characteristics and noise characteristics,a new method based on amplitude modulation and cyclic cross-correlation is proposed.Under the condition of low output signal to noise ratio(SNR)of QD,this method can accurately measure the photocurrent amplitude of each quadrant of QD and calculate the accurate spot position.Experiments results show that,when the output SNR of QD is-14.58 dB,the absolute error of this method is less than 0.012 mm,the effectiveness of the method is proved.
作者
李庆
徐少雄
彭真明
黄永梅
LI Qing;XU Shaoxiong;PENG Zhenming;HUANG Yongmei(Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China;School of Information and Communication Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China;Key Laboratory of Optical Engineering,Chinese Academy of Sciences,Chengdu 610209,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《光通信技术》
北大核心
2020年第2期6-9,共4页
Optical Communication Technology
基金
国家自然科学基金（批准号：U1738204）资助
关键词
空间光通信
光学天线控制系统
四象限探测器
循环互相关
space optical communication
optical antenna control system
quadrant detector
cyclic cross-correlation
