Coupling system with concave and positive–negative angular cone lenses group for the Cassegrain receiving antenna system

Abstract

In space optical communication system, the beam received by the Cassegrain receiving antenna needs to be coupled into the single-mode fiber before being detected. In this paper, a concave lens and a set of positive–negative angular cone lenses structure are designed to change the hollow beam generated by the Cassegrain receiving antenna into a solid beam. The coupling efficiencies for the hollow beam and solid beam are analyzed and numerically simulated. The simulation results show that the coupling efficiency can be improved and reaches the optimum value 0.808 after the hollow beam is changed into solid beam. Moreover, when the coupling lens and the fiber are not perfectly aligned, the coupling efficiency of the solid beam is larger than the hollow beam. The research results provide a way to improve the coupling efficiency of the Cassegrain receiving system and have practical application in the space optical communication system.