SUBSTRATE WITH RARE EARTH ION AND ALKALI METAL ADDITION TYPE GLASS FILM AND WAVEGUIDE FORMED BY USING THE SAME AND ITS PRODUCTION

摘要

PURPOSE:To provide the substrate with a rare earth ion and alkali metal addition-type glass film which has a large specific refractive index difference, affords high fluorescence efficiency, is low in softening point temp. and is in expensive as well as the waveguide formed by using this substrate and the process for production of this waveguide. CONSTITUTION:A porous film 3 of a SiO2-based glass is formed on the substrate 1 having a low refractive index layer 2. This porous film 3 is impregnated with an aq. soln. MeO.nSiO2-xH2O (Me; alkali metal) of an alkali metal silicate contg. a rare earth element in the porous film 3 and is then dried and sintered, thereby a glass film 5 is formed.