Bin Li(李斌)1,2,3, Wen-Hao Yu(于文豪)1,2,3, Mo Chen(陈莫)1,2,3, Jin-Long Tang(唐金龙)1,3, Hao Xian(鲜浩)1,3
1 Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, Chengdu 610209, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China; 3 The Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
Abstract In this paper, an active optics and co-focus experimental system of segmented mirror is built. Firstly, a support structure of segmented mirror is designed and it is verified by simulation to meet the requirement for the experimental system of segmented mirror. In this system, the large de-focus and tilt/tip errors of the segmented mirror are adjusted by observing the density and contrast of interference fringes based on isoclinic interference theory until the defocus and tilt/tip errors are in the detective range of the Shack-Hartmann. Then, the Shack-Hartmann is used to measure them and they are adjusted by actuators. The actuators are controlled by active optics to realize the closed-loop adjustment and maintenance for fine co-focus of segmented mirror. And the interference fringes are utilized to verify the detective precision of Shack-Hartmann. After the co-focus fine-tuning of the segmented mirror, the tilt/tip residual surface error is better than 0.01λ RMS; the defocus residual surface error is better than 0.01λ RMS.
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