卫星激光通信均匀信标光的研究

采用信标光是完成卫星激光通信捕获过程的一种重要手段,信标光的远场分布对捕捉概率和捕获时间有较大的影响。为满足通信系统的性能要求,对信标的远场分布提出一定的要求是必要的。首先从理论计算的角度,分析了远场高斯分布信标光对卫星激光通信捕获过程的影响,认为在存在光束抖动的情况下,均匀信标光在捕获阶段具有明显的优势。基于多激光器合束技术,利用半导体激光器设计了一个能实现远场均匀分布的信标光模块。给出了模块结构,分析了均匀信标光产生的机理,并从理论上推导了该模块的远场光强分布表达式。实验表明,所研制的均匀信标光模块可出射功率超过3.8 W,不均匀度小于11%的远场均匀信标光,通光效率为54%,从而证明了所设计的信标光模块的可行性。

Study on the Uniform Beacon Used for the Free Space Laser Communication

Using a beacon in the free space laser communication system is an important method of finishing the acquisition course.The far-field distribution of a beacon affects seriously the acquisition time and acquisition probability.In order to satisfy practical performance requirements,it is necessary to design the far-field distribution of a beacon.First,the impact of a far-field Gaussian distribution beacon on the acquisition course of laser communication is analysed and the far-field uniform beacon has some advantage compared with the far field Gaussian beacon in the case of transmitting beam jitter.One kind of far-field uniform beacon model is developed on the base of combination of semiconductor lasers.The structure of the model is described,the operating principle of model is analysed and the far-field distribution expression of the beam is derived.Experiment's data indicate that transmitting power of the model is more than 3.8 W,the degree of non-uniformity is less than 11% and the coupling efficiency is 54%,so the feasibility of the model is proved.