自适应光纤耦合器(AFC)是一种可实现高稳定、高效的空间光至光纤耦合的新型自适应光学器件。研究了AFC阵列作为空间激光通信系统接收光端机的可行性。在不同的大气湍流强度下,利用SPGD算法,仿真研究了不同子孔径数AFC阵列的闭环控制过程。研究结果表明,AFC阵列技术可缓解大气湍流影响,改善光纤耦合效率并提高耦合过程的稳定性;当等效接收口径一定时,随着阵列子孔径数的增加,光纤耦合效率及控制算法收敛速率都相应提升。
Adaptive fiber coupler(AFC) is a new kind of fiber-based adaptive-optics device which can achieve high and steady efficiency in coupling laser beam from space into fibers. Analysis on the feasibility of adopting AFC array as receiver in free space laser communications was studied. Simulation research on the closed-loop control process of AFC array with different number of sub-units using SPGD algorithm under different turbulence conditions was achieved. Simulation results show that:(1) adopting AFC array as receiver can realize high and stable coupling efficiency and alleviate the effects of atmospheric turbulences;(2) coupling efficiency and the algorithm convergence rate promote as the number of the array increases, where the equivalent aperture of the receiver is certain.