为了解决远距离能量传输问题, 当空间激光通信终端搭载卫星平台时, 激光光束的发散角通常都非常小, 典型的为 10 μrad量级。但是在地面近距离测试中, 必须适当的放大发散角, 以保证在一定跟踪精度下, 通信终端始终能在信标和通信光束指向范围内。本文以对波前光强分布最为敏感的通信光为例, 对不同通信距离和不同位置的光强分布进行理论建模和模拟仿真, 分析其对通信的影响, 为空间激光通信地面测试提供科学的试验方法和试验思路。同时, 对比离焦和固定倍率两种发散角放大方法的优劣, 以某空间激光通信光端机地面测试为例, 给出优化实现方案及结果, 为空间激光通信地面测试进一步积累经验。

In order to solve the problem of long distance energy transmission, divergence angle of laser transmitted by space-borne laser communication terminal must be usually very small, typically on the order of tens of microradians. But the ground testing must properly amplify the divergence angle, to ensure that the communication terminal can always in the beacon beam and communication beam range with a certain tracking accuracy. This paper uses the communication light which sensitive the intensity distribution as an example, building the theory molding and simulating for different distance and position, analyzing the influence, which provides scientific basis for space laser communication ground demonstration. Meanwhile, defocus and magnification of two kinds of divergence angle amplification method was compared. In the ground testing of a space laser communication, we give the optimal selection scheme. The result provides scientific basis and accumulated experience for the space laser communication ground test.