The Study Of Co-phasing Alignment Technology For Segmented Telescope

Large aperture optical element manufacturing is the necessiry way to achieve high resolution tecescope.The larger of the mirror,the processing difficulty is increased by the geometric progression,so segmented primary mirror is proposted to solve this problem,and this method is the development trend of large aperture optical telescope.Compared with the telescope system consisting of a single primary mirror,the telescope system consisting of segmented mirrors also brings some new problems while increasing the diameter of the telescope.Analysis the characteristics of the segmented mirrors to provide theoretical support for the co-phasing detector,is the foundation to achieve segmented optical system.This paper focuses on a series of studies on the co-phasing detection and assembly of segmented mirrors.The main research contents can be divided into the following parts.An improved dual-wavelength interferometer is proposed for the cophasing detection of segmented primary mirror,analyzed the principle of the optical system.An auxiliary optical system with switchable lens is proposed and designed,the simulation analysis is carried out by using multiple structures of the optical software.In order to ensure the errors that may occur during the switching process,analyze the tolerance of the interference system,and the result shows this method is useable.This method reduce the factor which may affects the cophasing error of segmented primary mirror,and improves the detection accuracy while expanding the dynamic range of the interference detection.Based on the theoretical analysis,a Cassegrain optical system with the primary diameter of 616 mm is designed and manufactured,and designed the adjustment for the segmented mirror;based on the improved dual-interferometer,the wavefront error reconstruction method based on the single interferogram is proposed,simulated and analyzed the algorithm of wavefront misalignment,verified the accuracy of algorithm,and analysied the correspondence between mirror misalignment and movement of segmented mirror adjustment.The optical test platform for the segmented mirror is built and obtains some valid experimental data,and also validates the reliability of the preliminary design,provides a new method for the co-phase adjustment of large aperture segmented mirrors.