卫星激光通信需要进行端机远场模拟及远场测试技术研究。在室内短距离模拟远场分布的测试系统中,可以采用透镜变换,在透镜焦平面处得到远场分布。实际测试时引入点光源及平面反射镜,保证焦面位置确定的准确性。模拟卫星激光通信端机平行出射光的远场光斑,经实验检测,光斑第一、二、三级暗纹直径与远场光斑理论值比较的相对误差均小于5%。这表明,该方案可以准确模拟和测试端机远场。该研究工作对卫星激光通信捕捉概率的研究、通信研究、光链路功率的实测核准以及端机性能的整体评估有重要意义。
Simulation of far-field pattern (FFP) of a terminal is needed for the free-space laser communication. Hence a measuring system which uses a point source and a mirror to get the FFP from the focal plane of a lens is established. The measurements of FFP's first, second, third dark ring diameters have a relative error less than 5% comparing with the theory ones, which proves that the method can simulate the FFP of the terminal precisely. The method is useful for researches on acquisition probabilities and power computation of an optical inter-satellite link (ISL). It is also useful for the judgement of the free-space laser communication terminal.