Analysis and simulation of the surface shape of membrane mirror applied by non-uniform load

Abstract

Research and manufacture of large aperture and lightweight telescope is urgently needed with the development of space optical system and the requirement for high resolution, and becomes one of the main tasks in space science area in future. The membrane mirror with a substrate of flexible film has characteristics of lightweight, compact-deployable and low cost compared to the traditional one and it is prospected to be applied in future large space optical systems. The surface shape control is one of the key technologies for the manufacture of membrane mirror. Based on the previous research works carried out in our lab, the surface shape of membrane mirror applied by non-uniform load is theoretically analyzed and simulated in the membrane mirror's surface shape control system in this paper. The construction of the system and the realization of the functions are described in detail. The analysis and simulation of surface shape control of membrane mirrors with 300mm aperture and different F numbers are performed applied by both non-uniform load and uniform load in the control system. The results of the simulation show that the RMS wavefront error of the membrane mirror under non-uniform load can be controlled and improved in two orders of magnitude comparing to that of the membrane mirror under uniform load, which is prospected to be a viable method for the design and manufacture of large aperture and lightweight membrane mirror with high surface accuracy.