高波前拟合精度的紧凑型音圈变形镜

Compact voice coil deformable mirror with high wavefront fitting precision

为了满足小型化自适应光学系统校正波前畸变的需求,基于系统理论分析设计了一种使用微型音圈驱动器的变形镜。使用电磁理论和有限元方法优化了微型音圈驱动器的结构参数。从热变形、共振频率、耦合系数等多个参数的角度对变形镜进行了优化。最后根据影响函数完成了波前拟合和残差计算。优化后的69单元紧凑型音圈变形镜具有大相位调制量、良好的热稳定性,第一共振频率为2220 Hz。对于PV值为1μm的前35项泽尼克模式,紧凑型音圈变形镜的拟合残差均小于30 nm。对于复杂随机像差,紧凑型VCDM能够将波前RMS降至原来的10%以下。结果表明,与传统的音圈变形镜相比,紧凑型音圈变形镜具有更高的波前拟合精度。高性能、低成本的紧凑型音圈变形镜在视网膜成像和机载成像系统中具有良好的应用前景。

To meet the requirements of wavefront distortion correction for miniaturized adaptive optics systems,a Deformable Mirror(DM)using micro voice coil actuators was designed based on systematic theoretical analysis.The structural parameters of the micro voice coil actuator were optimized by electromagnetic theory and the finite element method.The DM was optimized with respect to thermal deformation,resonance frequency,coupling coefficient and other parameters.Finally,wavefront fitting and residual calculation were completed according to the influence function.The optimized 69-element Voice Coil Deformable Mirror(VCDM)has a large phase stroke,good thermal stability,and a large first resonance of 2220 Hz.The RMS of the fitting residuals of the VCDM for the first 35 Zernike modes with a PV value of 1μm are all below 30 nm.For complex random aberrations,the compact VCDM can reduce the wavefront RMS to less than 10%.Compared with a traditional VCDMs,the results of our compact VCDM indicate that it has a higher wavefront fitting precision.The compact VCDM with high performance and low cost has good potential applications in human retinal or airborne imaging systems.