光束腰半径对空间相干光通信外差效率的影响

外差效率是影响相干光通信的重要因素，研究中入射光为艾里斑分布，以高斯光为本振光为基础建立了外差效率模型，研究了高斯光束腰半径变化对外差效率的影响，并进行了仿真。结果表明，探测器半径和束腰半径的比值是1.53，且束腰半径和系数F的比值是0.8时，可以实现约为83.3%的最佳外差效率。光束腰半径的变化对外差效率的影响较大，随着本振高斯光束腰半径的继续增大，外差效率迅速降低，即系统性能严重下降。该研究对相干光通信技术中外差效率的研究具有重要的指导意义。

Effect of Beam Radius on Heterodyne Efficiency for Space Coherent Optical Communication

Heterodyne efficiency is one of the important factors in coherent optical communication. A model of the het-erodyne efficiency was established based on the precondition of the incident beam as Airy distribution while local oscilla-tor beam as Gauss beam. The relationship between Gauss beam radius and heterodyne efficiency is studied, and the simulation results show that the system can get the optimal heterodyne efficiency of 83.3% while the ratio of optoelec-tronic sensor surface radius to the Gauss beam radius is 1.53 and that of Gauss beam radius to the system number F is 0.8. The Gauss beam radius can impact the heterodyne efficiency seriously. The heterodyne efficiency decreases rapid-ly with the increase of Gauss beam radius. So the system performance seriously declines. This study has important guiding significance to heterodyne efficiency in coherent optical communication.