高隔离度激光通信终端光学系统设计

Design of optical system of high isolation laser communication terminal

激光通信具有信息容量大、光学增益高、高度抗干扰和抗截获能力等突出优点,是解决高速通信问题的重要技术手段。根据激光通信中收发一体、双向双工工作模式对收发隔离度的要求,通过对不同光学结构隔离度仿真分析后,提出采用离轴三反光学天线降低后向散射从而实现高收发隔离度,在光学设计时,通过迭代优化控制光学表面上最小入射角,以及对光学表面精细加工工艺提出了明确的指标要求,最终实现了隔离度≥70 dB。仿真分析得出物方视场角5 mrad隔离度为73.7 dB,实测Φ150 mm离轴三反光学天线的隔离度可达73 dB,与仿真分析的结果一致,满足卫星激光通信系统捕跟和通信对光线天线隔离度的要求,可用于星间激光通信。

Laser communication has outstanding advantages such as large information capacity,high optical gain,high anti-interference and anti-interception capabilities.It was an important technical means to solve highspeed communication problems.According to the requirements of transceiver isolation and two-way duplex working mode in laser communication.After simulating and analyzing the isolation of different optical structures,it was proposed to use off-axis three-mirror optical antennas to reduce backscattering to achieve high transceiver isolation.In the optical design,the smallest incident angle on the optical surface was controlled through iterative optimization,and clear index requirements were put forward for the fine processing technology of the optical surface,and finally the isolation was more than 70 dB.The simulation analysis shows that the object field angle of 5 mrad isolation is 73.7 dB,and the measured isolation ofΦ150 mm off-axis three-mirror optical antenna can reach 73 dB,which is consistent with the results of simulation analysis.It meets the requirements of satellite laser communication system tracking and communication for light antenna isolation,and can be used for inter-satellite laser communication.