用于4米级主镜制造的主动应力研磨盘的变形验证与表面改进

Deformation verification and surface improvement of active stressed lap for 4 m-class primary mirror fabrication.

作者信息

Zhao Hongshen, Li Xiaojin, Fan Bin, Zeng Zhige

出版信息

Appl Opt. 2015 Apr 1;54(10):2658-64. doi: 10.1364/AO.54.002658.

DOI:10.1364/AO.54.002658

Abstract

The surface shape accuracy of the active stressed lap impacts the performance of grinding and polishing in the fabrication of large mirrors. We introduce a model of active stressed lap for the fabrication of a 4 m f/1.5 mirror based on finite element analysis (FEA), and the lap surface accuracy achieves RMS<1.8 μm in the FEA method. Using the lap surface measurement system, experimental verification is put forward, and the RMS of the measured lap surface is within 2 μm in practice. A general improvement in lap surface accuracy using the Zernike polynomial is shown. After compensating the calculation errors, the lap surface accuracy is improved by 8%-23%, and achieves RMS<1.5 μm, which is appropriate for practical grinding and polishing.

摘要

主动应力研磨盘的表面形状精度会影响大型镜面制造中研磨和抛光的性能。我们基于有限元分析（FEA）引入了一种用于制造4米f/1.5镜面的主动应力研磨盘模型，在FEA方法中研磨盘表面精度达到均方根误差（RMS）<1.8μm。利用研磨盘表面测量系统进行了实验验证，实际测得的研磨盘表面RMS在2μm以内。结果表明使用泽尼克多项式可总体提高研磨盘表面精度。在补偿计算误差后，研磨盘表面精度提高了8%-23%，并达到RMS<1.5μm，适用于实际的研磨和抛光。