Influence of aberrations of receiver antenna on heterodyne efficiency in free-space optical communications based on heterodyne detection

Heterodyne efficiency in free-space optical communications based on heterodyne detection is degraded by the aberrations of the optics antenna used for reception of optical beams. The evolution of heterodyne efficiency with the change of rms of primary aberrations is investigated. It is shown that heterodyne efficiency decreases gradually with increasing primary aberrations. The comparison shows that different aberration types have variant influence on heterodyne efficiency. In addition, obscuration ratio of receiver antenna has a noticeable but relatively minor influence on heterodyne efficiency. We hope this work can benefit system design of heterodyne receiver in free-space coherent communications.