Investigation into factors affecting the surface reflection phenomenon of aspherical mirrors and improvement...

Spherical/aspherical mirrors are widely used in optical and imaging systems, but their reflectivity is affected by surface morphology. In order to improve the reflectivity of the mirror surface, this paper systematically studied the factors that cause diffraction effects on the mirror surface. First, a surface morphology model for ultra-precision turning of spherical/aspherical mirrors was established. Then, based on the surface morphology model, a reflectance model of the mirror surface was established. The diffraction effect on the surface of the mirror was simulated, and the core factor causing the diffraction effect on the mirror surface, namely the P-V value of the surface morphology, was obtained. In response to the broadband application requirements of spherical and non-spherical aluminum alloy mirrors in the visible to near-infrared wavelength range, the peak-to-valley value (Rz value) of the ultra-precision machined surface can be controlled within 13 nm to effectively suppress the diffraction effect on the mirror surface. This ensures that the specular reflectance of the mirror surface remains above 90%, thereby achieving effective suppression of diffraction phenomena. The relevant simulation results have also been experimentally verified, and a planning algorithm for cutting interpolation points is proposed, successfully controlling the reflectivity of the mirror surface at around 94%. This paper provides a theoretical basis for processing high-reflectivity spherical/aspherical mirrors.