Development and theoretical analysis of novel center-inlet computer-controlled polishing process for high-efficiency polishing of optical surfaces

Abstract Although traditional computer-controlled optical surfacing (CCOS) technology has been successfully developed for polishing large aspheric optics, the polishing process continues to pose several challenges, including polishing tool wear and uneven distribution of polishing particles in contact areas. To improve the efficiency and stability of the polishing process, we present a novel center-inlet computer-controlled polishing (CCCP) process and tool for high-efficiency polishing of large-diameter aspheric optics. Compared with traditional CCOS, the most distinctive feature of CCCP is that the polishing slurry is supplied by the central hole of the polishing tool to improve its utilization efficiency. Moreover, a flexible coupling is used to connect the tool and motorized spindle to keep the tool in parallel with the work surface during the polishing process. The experimental apparatus and optimization design of the CCCP tool were first constructed based on CCOS. Then, the material removal mechanisms were explained by a series of theoretical and experimental studies. Results indicated that CCCP can improve the wear resistance of the polishing pad and make fuller and more even abrasive grain supply compared with traditional CCOS. The innovative theoretical model was verified and used for optimizing the epicyclic tool motion in CCCP. The experiments indicated that CCCP can produce a higher material removal rate and a better surface state than can CCOS.