确定性光学加工中抑制边缘效应的一种方法(英文)

在确定性光学抛光过程中,当加工到工件边缘时由于工艺条件发生变化会产生边缘效应,导致加工效率降低和面形误差增大.针对这种情况,提出了一种可修正边缘现象的球形工具抛光技术,其去除函数稳定性较好,形状趋于高斯分布且束径也较小,对修正边缘现象以及局部面形误差具有较好的效果.同时规划了其抛光路径,采用一种伪ρ-θ光栅扫描运动方式的加工路径,简化了球形抛光工具的结构,并且由于使加工纹路有了变化,可使加工后的表面纹理呈现无序性和均匀性特征,相应可提高加工后工件的表面质量.最后通过对一块微晶球面镜的加工(面形误差峰谷值PV由加工前1.607λ(λ=632.8 nm)收敛到加工后0.365λ,均方根值RMS由0.195λ收敛到0.024λ),验证了球形抛光工具具有修正边缘翘边现象的能力.

A Method for Correcting Edge Effect in Deterministic Optical Manufacturing

In the process of deterministic optical manufacturing, the edge effect will arise because of the change of machining conditions when polishing face accuracy of workpiece and debase machining tool locates in edge area, which will lower the sur efficiency. Aiming at the situation, a spherical polishing technology is presented for the control of edge effect. The removal function of spherical tool has fine stability and small diameter, with a shape similar to Gaussian distribution, which is greatly suit- able for correcting local errors and removing the edge effect of optical elements. The polishing route of the spherical polishing tool is planned by using pseudo p-O raster scanning method. The route can simplify the moving structure of the spherical polishing tool, homogenize machining texture and improve ma chining quality correspondingly. Finally, the figuring ability of the spherical polishing technology is validated by a correcting experiment on edge error. In the experiment, a crystallitic spherical mirror was polished by using the spherical tool, a severe edge effect was eliminated effectively, the peak-to- valley value （PV） of residual errors was reduced from 1.607A to 0.365A, and the mean-square-root value （RMS） was reduced from 0.195A to 0.024A（λ=632.8 nm）.