针对激光通信系统对光混频器的特殊需求, 设计并完成了一种信号光采用空间光输入、本振光采用保偏光纤输入的90°混频器。该器件信号端输入的空间光的束腰直径为10 mm, 信号光插入损耗小于3.1 dB, 本振光插入损耗小于2.5 dB, 在指定工作波长处I路和Q路的相位差满足90°±5°。实验结果表明, 该器件能够满足激光通信对于混频器的性能需求。

In view of the special requirements of laser communication systems for optical mixers,this paper designs and completes a 90° mixer, with the signal light by spatial light input and the Local Oscillating(LO) light by polarization maintaining fiber input.The beam waist diameter of the spatial light introduced from the signal end of the device is 10 mm, the insertion loss of the signal light is less than 3.1 dB and that of the LO less than 2.5 dB. At the specified operating wavelength, the phase difference between branch I and branch Q satisfies 90°±5°.The experimental results show that this device meets the requirements of laser communication for mixer performances.