An Optical Surfacing Technique of the Best-fitted Spherical Surface of the Large Optics Mirror with Ultra Precision Polishing Machine
대형 광학계 연마 장비에 의한 대구경 반사경의 최적 근사 구면 제조 방법에 관한 연구

Chang Kyu Song, Gyungho Khim, Jooho Hwang, Byung Sub Kim, Chun Hong Park, Hocheol Lee
2013 Journal of the Korean Society for Precision Engineering  
This paper describes a novel method to surface large optics mirror with an extremely high hardness, which could replace the high cost of the repetitive off-line measurement steps and the large ultraprecision grinding machine with ultra-positioning control of 10 nm resolution. A lot of diamond pellet to be attached on the convex aluminum base consists of a grinding tool for the concave large mirror, and the tool was pressured down on the large mirror blank. The tool motion at an interval on the
more » ... piral path was controlled with each feed rate as the dwell time in the conventional computer-controlled polishing. The shape to be surfaced was measured directly by a touch probe on the machine without any separation of the mirror blank. Total 40 iterative steps of the surfacing and measurement could demonstrate the form error of RMS 7.8 µm, surface roughness of Ra 0.2 µm for the mirror blank with diameter of 1 m and spherical radius of curvature of 5400 mm.
doi:10.7736/kspe.2013.30.3.324 fatcat:updrelijarer3mqnakwmznp5nu