湍流下自由空间光通信的光纤耦合效率及补偿

Fiber Coupling Efficiency for Free Space Optical Communication Through Atmospheric Turbulence and Compensation

采用光纤部件的自由空间光通信系统需要把接收到的光束耦合进单模光纤中,然而由于大气湍流的影响,使光纤耦合效率下降。本文把基于大气湍流参数的单模光纤耦合效率表达式推广到斜程传输情景,仿真了耦合效率与湍流强度及传输距离和天顶角之间的关系。为了补偿湍流效应,提高光纤耦合效率,本文提出了用一种新颖的无模型盲优化波前校正技术,用随机并行梯度优化算法实时控制变形镜,把校正后的光耦合进单模光纤,使单模光纤耦合效率最优化。结果表明此系统能使单模光纤耦合效率得到显著地提高。

The received laser beam in a free-space optical communication using fiber-optic components system must be coupled into a single-mode fiber. However, propagation through atmospheric turbulence degrades the fiber-coupling efficiency. Single-mode fiber coupling efficiency of expression as a function of atmospheric turbulence parameters is extended to the oblique propagation scenarios, and the coupling efficiency as functions of turbulence intensity, transmission distance and zenith angle is simulated. To compensate for turbulence effects and improve fiber coupling efficiency, this paper use a novel model-free blind optimization wavefront correction with random parallel gradient optimization algorithm to control deformable mirrors and couple the corrected light into the single-mode fiber, so single-mode fiber coupling efficiency is optimized. The results show that single-mode fiber coupling efficiency is significantly improved.