渐变厚度主动变形镜的研究

Active Deformation Mirror with Variable Thickness

为了简化空间相机在轨高分辨率成像的促动方案,提出基于渐变厚度形式的主动变形镜双促动结构。首先根据弹性力学理论,建立波前像差表示方法与变形镜渐变厚度的理论关系,可以求解出各种像差模式所需的厚度分布。然后通过结构建模、有限元分析、面型拟合计算和光学性能评估的光机力一体化模拟仿真,定量化评估像差的补偿效果。最后设计渐变厚度变形镜光机结构方案和驱动方案,采用两个促动器来实现球差与像散的校正。变形镜受力形变实验结果表明,双促动变形镜可产生较好的球差与像散,能够避免印透效应,有效补偿自身的加工误差与光学系统的波前误差。

In order to simplify the actuation scheme of on-orbit high resolution imaging of space camera,a dual actuation structure of active deformation mirror based on the form of variable thickness is proposed.First,according to the theory of elasticity,the theoretical relationship between the wavefront aberration representation method and the variable thickness of the deformed mirror is established,and the thickness distribution required by various aberration modes can be solved.Then,the effect of aberration compensation is quantitatively evaluated through structural modeling,finite element analysis,surface fitting calculation and optical performance evaluation.Finally,the structure scheme and the driving scheme of the variable thickness deformation mirror optical machine are designed.Two actuators are used to realize the correction of spherical aberration and astigmatism.The deformation experiment results show that the dual-actuated deformation mirror can produce better spherical aberration and astigmatism,avoid the impression effect,and effectively compensate its own machining error and wavefront error of optical system.