用于在线检测的紧凑型瞬态干涉测量系统

Compact transient interferometric measurement system used for online testing

针对不同口径光学元件加工阶段的在线测量需求,提出了用于在线检测的紧凑型瞬态干涉测量系统。系统引入偏振相机来实现波前瞬态移相干涉测量以降低外界扰动影响。同时结合基于位形优化算法的子孔径拼接技术,可降低对运动扫描平台精度要求,并实现大口径光学元件全口径检测。为验证所提出测量系统的可行性,分别对金刚石车削机床对中工具和大口径球面镜进行在线检测和子孔径拼接测量,结果表明,与ZYGO干涉仪检测结果相比,两者对应的均方根值偏差的绝对值分别为0.003与0.007μm。同时该系统具有布局结构紧凑和对外界环境扰动不敏感的特点,可很好地满足复杂环境在线安装检测应用要求,在金刚石车削机床对中工具的在线调整和不同口径光学元件在线检测中具有较广泛的应用。

Aiming at the online testing needs of optical elements with various optical aperture sizes during processing stage, a compact transient interferometric measurement system used for online testing is proposed. A polarization camera is applied to realize the transient phase-shifting interferometric measurement of wavefront and reduce the effect of environmental disturbance. Combining the subaperture stitching technique based on configuration optimization algorithm, the accuracy requirement for the motion scanning platform is lowered and the full-aperture surface testing of large aperture optical elements can be achieved. To verify the feasibility of the proposed system, the online testing and subaperture stitching measurement of the centering tool of diamond turning machine and a large aperture spherical mirror were carried out, respectively. The results show that compared with the detection results of ZYGO interferometer, the absolute deviations of the corresponding root mean square values for the two cases are 0.003 and 0.007 μm, respectively. The system features compact layout and insensitivity to external environmental disturbance. The proposed system can nicely meet the application requirements of online installation and testing in complex environmental condition, and has wide application in online adjustment of centering tool of diamond turning machine and online testing of the optical components with various aperture diameters.