Bit-error rate (BER) performance of free-space optical communication (FSO) systems is compromised by pointing errors. Few-mode fiber (FMF) based receiver emerges as a promising solution for FSO, because FMF can obtain high coupling efficiency in the presence of pointing errors. The high coupling efficiency allows FMF based system to achieve improved BER performance. In this letter, based on a simplified mode demultiplexer model, we propose a method to use the coupling efficiencies of each mode of FMF to characterize the BER of the FMF based FSO system having nonzero boresight pointing errors. We find that the boresight displacement can significantly deteriorate the BER performance, and the jitter variance can reduce the impact of boresight within a suitable range.

中文翻译：

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具有非零视轴指向误差的基于少模光纤的自由空间光通信


自由空间光通信 (FSO) 系统的误码率 (BER) 性能会受到指向错误的影响。基于少模光纤 (FMF) 的接收器成为 FSO 的一种有前景的解决方案，因为 FMF 可以在存在指向误差的情况下获得高耦合效率。高耦合效率使基于 FMF 的系统能够实现更高的 BER 性能。在这封信中，基于简化的模式解复用器模型，我们提出了一种使用 FMF 每种模式的耦合效率来表征具有非零视轴指向误差的基于 FMF 的 FSO 系统的 BER 的方法。我们发现视轴位移会显着恶化BER性能，而抖动方差可以在合适的范围内减少视轴的影响。