光子学报, 2018, 47 (2): 0212003, 网络出版: 2018-01-30
拼接镜主动共相实验研究
Cophasing Experiment of Active Optics for Segmented Mirror
天文光学 望远镜 子孔衍射 拼接镜 共相 主动光学 Astronomical optics Telescope Subaperture diffraction Segmented mirror Cophasing Active or adaptive optics
摘要
针对拼接型天文望远镜主镜的共相检测问题, 对宽窄带夏克哈特曼检测法在拼接主镜各子镜间平移误差的测量进行了理论与仿真分析, 并搭建了一套室内拼接镜的主动共相检测实验光路系统, 其中拼接镜是由4块对边长为100 mm、曲率半径为2 000 mm的正六边形球面反射镜组成.首先, 利用夏克波前探测器进行了拼接镜的精共焦误差的检测, 通过主动光学技术控制压电陶瓷促动器, 实现了拼接镜的精共焦的调节; 然后通过宽带共相检测实现了粗共相的检测; 最后, 通过窄带共相检测实现了精共相的检测, 并通过主动光学技术控制压电陶瓷促动器, 实现了共相的调节.实验表明:宽窄带夏克哈特曼检测法对拼接子镜平移误差测量量程达到几十微米, 共相检测精度达到15 nm, 满足拼接镜对平移误差的测量要求.
Abstract
In order to solve the prolem of cophasing detection for the segmented mirror of telescope, the piston errors measurement of segmented mirror by the broadband and narrowband ShackHartmann algorithm are theoretical analyzed and simulated, and an active optics and cophasing experiment system is built. The segmented mirror is consisted of four hexagonal segments with the flat to flat lengths of 100 mm and the curvature of radius is 2 000 mm. Firstly, the ShackHartmann is used to detect the errors of cofocus ,and the active optics is used to control piezoelectric actuators to realize the fine cofocus of segmented mirror. Then the broadband phasing algorithm is used to realize the measurement of corse cophasing of segmented mirror. Finally, the narrowband phasing algorithm is used to realize the measurement of fine cophasing of segmented mirror, and the active optics is used to control piezoelectric actuators to realize of the segmented mirror cophasing adjustment. The experimental results show that the range is dozens of micros and the measurement accuracy is better than 15 nm of broadband and narrowband phasing algorithm, which demonstrates that the methods are suitable for the segmented mirror cophasing measurement and adjustment.
李斌, 吴建, 刘燕德, 谢锋云, 陈莫, 鲜浩. 拼接镜主动共相实验研究[J]. 光子学报, 2018, 47(2): 0212003. LI Bin, WU Jian, LIU Yande, XIE Fengyun, CHEN Mo, XIAN Hao. Cophasing Experiment of Active Optics for Segmented Mirror[J]. ACTA PHOTONICA SINICA, 2018, 47(2): 0212003.