Performance comparison of two telescope configurations for backscattered light in space gravitational wave detection

In space-based gravitational wave detection telescopes, backscattered light generated by the optical elements of the telescope interferes with the received signals, affecting interference measurements. Therefore, the analysis and suppression of backscattered light are crucial issues that must be considered in the telescope. In this paper, the results of a numerical model and simulation analysis are compared to analyze the stray light performance of two existing optical design schemes for telescopes. The contributions of backscattered light from the four mirrors have been determined, and the surface roughness indicators for optical elements meeting the stray light requirements have also been derived. This work lays the foundation for the manufacturing of prototype telescopes.