The Computer-Controlled Chemical Polishing Techniques for Precision optics

The computer-controlled chemical polishing (CCCP) techniques based on the Marangoni effect have been developed to manufacture precision optics on polished fused silica surface. In this study, we present the Marangoni confined chemical-etching process in which the material removal on optical surfaces can be accomplished by etching with buffered HF solution. The process shows stable characteristics and good repeatability while the etching depth can be controlled in the order of ten nanometers. We also present the experimental results of this technology for fabrication of phase corrector and continuous phase plate. Results show that the CCCP's deterministic sub-aperture-polishing characteristics make it possible to correct the surface error and imprint complex phase structure with spatial scale-length of several millimeters onto optical surface.