光子学报, 2016, 45 (8): 0822001, 网络出版: 2016-09-12
环形线负载驱动变曲率反射镜技术
Annular Force Based on Variable Curvature Mirror Technique
光学变焦 无运动部件变焦 变曲率反射镜 环形线负载驱动 薄板弹性理论 有限元分析 Optical zooming Zooming without macroscopic moving elements Variable curvature mirror Annular force based actuation Elasticity theory of thin plates Finite element analysis
摘要
从薄板弹性理论出发, 对可实现曲率变化的环形线负载驱动模型进行分析, 给出了基于该模型的大镜厚比变曲率反射镜的形变方程.以较小的驱动力实现较大的中心形变为目标, 利用MATLAB软件对不同反射镜厚度、驱动环半径下的反射镜形变情况进行模拟计算, 结果表明, 反射镜厚度范围在2~4 mm之间、驱动环半径数值在反射镜有效半径1/2处最佳.以此为依据, 设计并研制了口径为100 mm、厚度为3 mm的铍青铜环形线负载驱动变曲率反射镜结构及原型样片, 给出了变曲率反射镜整体结构前10阶的振动模态分析结果.完成装配后, 反射镜原型样片的面形精度接近λ/30(λ为波长).对该结构进行极限曲率变化和面形精度保持的验证实验, 通过对变曲率反射镜结构进行改进, 环形线负载驱动能够实现超过30个波长(632.8 nm)的中心形变, 且面形精度的变化与反射镜中心矢高的变化呈弱相关.
Abstract
Based on the elasticity theory of thin plates, the basic analysis on annular line load model and deflection equations based on this model was given. Aiming to generate a large saggitus variation using a smaller force, mathematical analysis on different mirror thickness and actuate ring radius was done by using MATLAB, the corresponding optimal value is 2~4 mm and 1/2 mirror's clear radius. One QeB variable curvature mirror prototype, whose diameter and thickness is 100 mm and 3 mm respectively was designed, fabricated and the whole structure's first ten vibration mode analysis was given. The surface accuracy of the assembled prototype is nearly λ/30. Finally, the capability in altering curvature and maintaining surface figure accuracy was tested experimentally. By improving the variable curvature mirror structure, the QeB variable curvature mirror could provide a saggitus more than 30 wavelengths(632.8 nm) and the degradation of surface figure accuracy is weakly correlated to the variation of radius of curvature.
解晓蓬, 赵惠, 李创, 樊学武, 任国瑞, 柴文义, 许亮, 苏宇. 环形线负载驱动变曲率反射镜技术[J]. 光子学报, 2016, 45(8): 0822001. XIE Xiao-peng, ZHAO Hui, LI Chuang, FAN Xue-wu, REN Guo-rui, CHAI Wen-yi, XU Liang, SU Yu. Annular Force Based on Variable Curvature Mirror Technique[J]. ACTA PHOTONICA SINICA, 2016, 45(8): 0822001.