在光纤激光通信系统中, 为了克服准误差、随机角抖动误差、大气湍流像差对单模光纤耦合效率的影响, 本文设计了单模光纤章动跟踪耦合系统。首先基于模场匹配原理, 分析了径向偏差和光斑大小对耦合效率的影响。其次在理论分析的基础上, 对激光章动跟踪系统进行了设计, 主要包括激光器、准直镜、快速反射镜、耦合透镜以及光电探测器, 并以光电探测器的能量反馈完成了激光章动跟踪算法设计。最后搭建了实验平台, 对系统进行了实验测试。通过实验测试得到, 在激光章动跟踪时单模光纤的耦合效率为53.5%, 并测试了径向偏差以及光斑大小对耦合效率的影响, 得到了相应的曲线。耦合效率满足系统要求, 并且实验测试曲线与理论分析的仿真曲线基本一致。

In the fiber laser communication system, in order to overcome the influence of quasi-error, random angular jitter error and atmospheric turbulence aberration on SMF( single-mode fiber) coupling efficiency, a single mode fiber optic nutation tracking coupling system is designed. Based on the principle of mode field matching, the influence of radial deviation and spot size on coupling efficiency is analyzed. Secondly, based on the theoretical analysis, the laser nutation tracking system is designed, including laser, collimating mirror, fast mirror, coupling lens and photodetector, and the laser nutrient is completed by the energy feedback of the photodetector. Tracking algorithm is designed. Finally, an experimental platform is built and the system is tested experimentally. Through experimental tests, the coupling efficiency of single mode fiber is 53.5% in laser nutation tracking, the influence of radial deviation and spot size on coupling efficiency is tested, and the corresponding curve is obtained. The coupling efficiency satisfies the system requirements, and the experimental test curve is basically consistent with the theoretical analysis.