Influence mechanism of stitching mirror error on imaging quality of large aperture infrared diffractive telescope based on Fourier optics

This study focuses on the impact mechanism of segmented mirror errors on the imaging quality of large-aperture infrared diffractive telescopes. Given the limitations of traditional reflective telescopes in meeting high-resolution requirements, segmented mirror technology has emerged as a critical solution due to its multifaceted advantages. However, imaging quality is susceptible to errors introduced during the segmentation process. Based on Fourier optical theory, this research derives the expression for the point spread function (PSF) of segmented mirrors and analyzes the effects of translational errors, tilting errors, and gaps between submirrors on the PSF and Strehl ratio. Additionally, the Monte Carlo method is utilized to evaluate the comprehensive impact of these errors. The results demonstrate that these errors degrade imaging quality from various perspectives, providing theoretical support for the precise alignment and optimization design of segmented mirrors. This, in turn, contributes to enhancing the performance and facilitating the engineering applications of large-aperture infrared diffractive telescopes.