PRODUCTION OF OPTICAL WAVEGUIDE

摘要

PURPOSE:To enable simplification of a production process by impregnating only a part where an optical waveguide is formed in cellular glass with an additive capable of enhancing the refractive index of glass, then heat-treating the impregnated glass and densifying the heat-treated glass. CONSTITUTION:A pattern mask 2 having an opening (2a) in the shape of a waveguide is formed on the surface of cellular glass 1 and an additive 3 capable of enhancing the refractive index of the glass is then selectively added through the opening (2a) of the pattern mask 2 to the cellular glass 1 near the opening (2a). The cellular glass 1 to which the additive 3 is added is subsequently heat- treated and densified. In the aforementioned method, the cellular glass 1 is formed by a sol-gel method and the additive is a metal. The additive is preferably added in a step for impregnating the cellular glass 1 near the opening (2a) with a hydrolytic sol solution 3 of a metal alkoxide through the opening (2a) of the pattern mask 2. The density of the cellular glass 1 is preferably >=0.6g/cm<3> and <=2.0g/cm<3>. Examples of the metal used as the additive include Ge, Ti and Al.