中文摘要：

基于轨道角动量（OAM,orbital angular momentum）复用自由空间光（FSO,free-space optical）通信系统不可避免地受到大气湍流的干扰。针对OAM复用通信系统,提出一种基于Gerchberg-Saxton相位校正的大气湍流干扰影响补偿方法。利用Gerchberg-Saxton相位恢复算法校正由大气湍流导致的OAM态复用光波前相位扭曲。数值仿真结果证实,该方法很好地抑制了大气湍流引起的OAM态复用串扰。在大气湍流折射率结构指数常数Cn2〈2× 10^-15m^-2/3时,系统误码率比没有使用Gerchberg-Saxton算法的要下降2到3个数量级。

英文摘要：

It was shown that the quality of free-space optical communication system using OAM（orbital angular momentum） multiplexing was inevitably degraded by AT（atmospheric turbulence）. A wavefront phase correction based on Gerchberg-Saxton algorithm to mitigate the wave front phase distortion of the OAM-multiplexed system transmitting through AT was proposed. The simulation results show that the crosstalk caused by AT decreases by using the proposed scheme. When the refractive index structure constant of AT Cn2 is lower than 2 × 10^-15-m^2/3, the BER（bit error rate）performance is decreased by two or three orders of magnitude with the proposed scheme.