针对空间激光通信系统小型化设计的需求, 提出了使用雪崩二极管(APD)型四象限探测器实现跟踪与通信复用的方案, 用以降低通信系统的体积和功耗, 提高光能量的利用率。简述了系统总体方案的组成与工作原理, 在室内搭建测试平台, 对跟踪与通信复用模式下的数据采集、通信速率、极限灵敏度、跟踪精度等探测性能进行测试。结果表明: 采用靶面直径为4 mm的APD型InGaAs四象限探测器, 在曼彻斯特编码、强度调制/直接探测条件下, 通信速率可达10 Mb/s, 探测灵敏度为-35.4 dBm, 误码率为10-6。当光斑直径为四象限探测器光敏面直径的一半左右时, 光斑位置检测的最小分辨率为2 μm, 探测范围可达0.8 mm, 角分辨率为0.8 μrad。初步验证了使用APD型四象限探测器用于跟踪与通信复合探测技术的可行性, 为空间激光通信系统小型化设计提供技术支持。

Aimming at the space laser communication system requirement of miniaturization, a scheme of using the avalanche photo diode (APD) type four-quadrant detector to complete the tracking and communication is proposed. This communication system could effectively reduce the volume and power consumption and improve the light energy utilization. The overall scheme of composition and working principle are introduced, the experiment is established in laboratory, and the detection performance which includes data collection, communications rate, limiting sensibility, tracking accuracy is tested. Experimental results show that by use of the APD type InGaAs four-quadrant detector with photosensitive surface diameter of 4 mm, the communication rate is 10 Mb/s, the detection sensitivity is -35.4 dBm and the bit error rate is 10-6 under conditions of Manchester code, intensity modulation/direct detection. The minimum position resolution of the spot position detection is 2 μm, the detecting range of QD is about 0.8 mm, and the angular resolution is 0.8 μrad while the diameter of light spot is about half of the diameter of the photosensitive surface.The feasibility of using the APD type four-quadrant detector for simultaneous tracking and communication is demonstrated, which provides technical support for design of the whole space laser communication system requirement of miniaturization.