Performance analysis of an all-optical double-hop free-space optical communication system considering fiber coupling

In an all-optical double-hop free-space optical communication system, the outage probability and bit error rate are analyzed using a composite channel. The model involves atmospheric attenuation, atmospheric turbulence, pointing error, and fiber coupling efficiency. Based on analysis of the channel model and amplifier spontaneous emission noise, the outage probability and bit error rate are obtained. For an all-optical double-hop link, fiber coupling efficiency has an important impact on outage probability, especially at relatively short total link length. By compensating for three terms of wavefront distortions, the system outage probability significantly decreases. The communication performance is further improved by optimizing the receiving aperture diameter and beam width.