全口径环形抛光中方形元件的材料去除率存在从中心到边角位置越来越大的现象,致使抛光工件出现塌角的面形,影响了方形光学元件的面形质量。基于Preston方程,通过改变元件的多种运动轨迹,计算了方形光学元件全口径的材料去除率分布。通过分析发现:使方形光学元件在保持原有自转的同时沿抛光模径向或与径向有一定夹角的方向摆动,且附加在元件整个抛光面上的运动速度保持一致时,可使方形元件的材料去除率分布得更均匀。通过附加这种运动方式可以有效控制方形元件的塌角现象。

In full-aperture annular polishing, material removal rate increases from the center toward the edge of square optical, which leads to a collapse angle surface profile and affects the precision of the final surface. Several types of element motion trajectories were studied herein, and the material removal rate distribution of a full-aperture surface was calculated based on the Preston equation. Results show that the square optical element moves along the radial direction or in direction of a certain angle with respect to the radial direction while maintaining its original rotation, and the additional speed of individual points on the entire polishing surface remains consistent, making the material removal rate distribution of square optical element more uniform. Therefore, the collapse angle surface profile of the square optical element can be effectively controlled by the additional motion trajectories of elements.