During the conventional optical shaping process of fused silica, lapping is generally used to remove grinding damage layer. But this process is of low efficiency, it cannot meet the demand of large aperture optical components. Therefore, Inductively Coupled Plasma Processing (ICPP) was proposed to remove grinding damage layer instead of lapping. ICPP is a non-contact, deterministic figuring technology performed at atmospheric pressure. The process benefits from its ability to simultaneously remove sub-surface damage (SSD) while imparting the desired figure to the surface with high material remove rate. The removing damage capability of ICPP has preliminarily been confirmed on medium size optical surfaces made of fused silica, meanwhile serious edge warping was found. This paper focused on edge effect and a technique has been designed to compensate for these difficulties. Then it was demonstrated on a large aperture fused silica mirror (Long320mm×Wide370mm×High50mm), the removal depth was 30.2μm and removal rate got 6.6mm3/min. The results indicate that ICPP can rapidly remove damage layer on the fused silica induced by the previous grinding process and edge effect is effective controlled.

Date Published: 28 October 2016
PDF: 6 pages
Proc. SPIE 9683, 8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, 96830B (28 October 2016); doi: 10.1117/12.2244602

Published in SPIE Proceedings Vol. 9683:
8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies
Wenhan Jiang; Li Yang; Oltmann Riemer; Shengyi Li; Yongjian Wan, Editor(s)