Comparative analysis of the aperture averaging function between Cassegrain system and singular aperture system

In free-space optical communication, aperture averaging effect can be used to optimize receiver design. A variety of factors contribute to aperture averaging effect, such as the receiving aperture, the light source, and the turbulence link. Cassegrain system is usually used as the receiver. It is technically feasible to optimally design the light source according to Cassegrain system's aperture averaging function and the turbulent propagation path. The aperture averaging functions of Cassegrain system and single aperture system are analyzed in this paper. The results show that the average aperture function of Cassegrain system decreases significantly. Large obscuration ratio can significantly reduce the value of K
₀
function.