Product and process for molding glass lenses

Abstract

A glass preform, including a core glass adversely affected by interaction with a molding tool, is provided with a thin surface layer of glass components that are inert to the tool and have an index of refraction that matches the core glass. More specifically, the thin layer comprises glass components having respective indexes of refraction above and below the core index of refraction, in an amorphous mixture that matches the core index. According to certain features, the core glass is flint glass including greater than five percent by weight of titania, and the glass components include mixtures of silica or indium and tin oxide applied in a layer having a thickness between one hundred and one thousand angstroms. Other features of the invention provide a method for making the glass preform and a method for molding a precision optical element using the preform.

Dependencies are inferred from the claim text.