Corning Incorporated
Enhanced performance metallic based optical mirror substrates

Abstract:

A method for coating substrates is provided. The method includes diamond turning a substrate to a surface roughness of between about 60 .ANG. and about 100 .ANG. RMS, wherein the substrate is one of a metal and a metal alloy. The method further includes polishing the diamond turned surface of the substrate to a surface roughness of between about 10 .ANG. and about 25 .ANG. to form a polished substrate, heating the polished substrate, and ion bombarding the substrate with an inert gas. The method includes depositing a coating including at least one metallic layer on the ion bombarded surface of the substrate using low pressure magnetron sputtering, and polishing the coating to form a finished surface having a surface roughness of less than about 25 .ANG. RMS using a glycol based colloidal solution.