Computer controlled optical surfacing technology research of mid-spatial frequency errors on large-aperture planar optical components

摘要

Based on the theoretical model of small-tool polishing, this paper studied the influence of polishing parameters on the results of computer controlled optical surfacing. We compared different parameters of the removal function and the tool path and analyzed the residual mid-spatial frequency errors in the polishing process. The simulation results indicated that raster path combined with Gaussian removal function, contributing to high accuracy of PSD 1 RMS, but leading to serious peaks of 1D PSD1 curves in some frequency points. In contrast, pseudo-random path combined with flat-topped removal function, resulting in lower accuracy of PSD1 RMS, but could effectively restrain the amplitude of the ID PSD1 curves. Finally, experimental study was carried out on both of the 610 mm × 440 mm K9 material transmission mirror and 430 mm × 430 mm fused silica plane window, the RMS value of PSD1 converged from 3.72 nm to 1.61 nm, and decreased from 2.30 nm to 1.37 nm, respectively, which demonstrated the correctness of the model.