曲率半径干涉测量定焦误差分析

Position Error Analysis in Radius Interferometric Measurements

为了提高曲率半径定焦准确度,从移相干涉仪,标准镜头透射波前误差,被测光学元件表面面形误差及调整误差等方面出发,分析影响干涉仪定焦准确度的各因素,并给出各误差补偿表达式.通过对比实验发现,在猫眼及共焦位置处调整误差补偿后,离焦量及曲率半径测量结果的变化趋势由近似线性变为随机变化,同时由离焦量引入的曲率半径变化量由7.05μm减小为0.5μm.在曲率半径干涉测量中,调整误差为影响定焦准确度的主要误差源,调节调整误差可有效控制离焦量的变化,提高曲率半径测量准确度.

In order to improve the position precision, a single analytical expression for position errors was presented in terms of the various error contributors, including phase measuring interferometer errors, wavefront errors of transmission sphere, surface deviation and adjustment errors. The contrastive experiments indicate that after controlling the adjustment errors, the linear trend of power and radius is changed to the random trend, and the radius variation is decreased from 7. 05 μm to 0. 5 μm. The adjustment errors are the main error contributors. The power can be effectively controled by minishing adjustment errors. Thus the interferometric radius precision is improved.