Abstract

Polished surface of optical glass has a tendency to deteriorate in the fabrication process. Typical deteriorations are dimming, staining and latent scratch. Dimming is formed due to the chemical reaction between glass and a small quantity of water such as condensed dew on glass surface. Staining is generated due to the chemical reaction between glass and relatively a large quantity of water. Soluble components are dissolved into water, and then a thin residual surface layer which has lower index than matrix glass cause interference color. And latent scratch is caused by over-all dissolution of glass surface. Tiny undetectable scratches formed in polishing process grow to detectable size as a result of surface dissolution in the ultra-sonic cleaning process.

© 1982 Optical Society of America