Ground simulation method for arbitrary distance optical transmission of a free- space laser communication system based on an optical fiber nanoprobe

Simulation technologies for optical transmission are used to simulate the course of laser long-distance transmission in space and reception by a free-space optical (FSO) communication terminal, which determines the receiving power and is one type of core technology for ground validation and detection. The simulated distance of the current optical transmission simulation methods is limited, and these methods fail to meet the continually increasing distance of FSO communication. In this paper, a method called “relay transmission” is proposed based on an optical fiber nanoprobe that can simulate an optical transmission at an arbitrary distance. Using this method, direct pointto- point performance tests using two optical terminals are realized in the laboratory, whose results are consistent with on-orbit results. The far-field pattern of the incident light is obtained by an off-axis multiband reflecting telescope system with a large aperture, and wave sampling is performed by an optical fiber nanoprobe whose powercollection aperture corresponds to that of the receiving antenna of the on-orbit terminal. The feasibility of the proposed method is demonstrated through theoretical analysis and a series of validation experiments.