Influence factors of optical surface roughness in traditional polishing process

Reducing the optical surface roughness is the key to improve the polishing quality of optical mirrors. Traditional polishing technology in ultra-smooth polishing glass has been used widely for a long time. In this paper, the theories of traditional polishing in polishing process were summarized. The problems in polishing procedure were analyzed and the influence factors of optical surface roughness were provided according to the polishing procedure of optical mirrors, and the relative measurements were pointed out. During the factors, polishing slurry and polishing pad are the important ones. Contrasting with former traditional polishing technology, roughness factors of new polishing slurry and polishing pad were analyzed and used in polishing process. The optical mirror of Ø246mm was polished in traditional technology with new polishing slurry and polishing pad, the obtained testing results were surface roughness 3.421nm before polishing and 0.613nm after polishing.