In free-space optical communication (FSOC), it is necessary to couple optical fibers for application in optical-fiber technology and devices. However, propagation through atmospheric turbulence degrades the single-mode-fiber coupling efficiency (CE). This degradation can be compensated by an adaptive optics (AO) system. In this paper, we analyze the influence of spatial and temporal characteristics of turbulence on the CE. Experiments along a 1 km urban link demonstrate that the CE increases from 5% without AO to 10%–25% in the AO closed loop at different times of day. We obtain an increase by factor 4 in the CE under weak turbulence conditions.

在自由空间光通信（FSOC）中，有必要将光纤耦合以用于光纤技术和设备中。但是，通过大气湍流传播会降低单模光纤耦合效率（CE）。这种降级可以通过自适应光学（AO）系统进行补偿。在本文中，我们分析了湍流的时空特征对CE的影响。沿着1 km的城市链路进行的实验表明，在一天的不同时间，在AO闭环中，CE的百分比从无AO的5％增加到10％–25％。在弱湍流条件下，我们在CE中获得了因子4的增加。