| 摘要 |
PURPOSE:To provide the waveguide which has a smaller size, lower loss and multi-functions by impregnating a metal alcoholate soln. contg. an additive for refractive index control and rare earth element into a glass layer and subjecting the layer to a drying and high-temp. heat treatment and thereby forming a transparent glass film specified in the refractive index. CONSTITUTION:The porous glass film 3 consisting of SiO2 or contg. the additive for refractive index control in the SiO2 is formed on a substrate 1 formed with a buffer layer 2 (refractive index n1) consisting of the SiO2 or contg. the additive for the refractive index control in the SiO2. The metal alcoholate soln. 5 contg. the additive for refractive index control and the rare earth element is then impregnated in the porous glass film 3 and is subjected to the drying and high- temp. heat treatment. A core layer having a refractive index n2 (n2>n1), for example, the core layer 8 having an approximately square shape is formed thereby by photolithography, dry etching process. The multifunction optical device of the small size, high reliability, high performance, and low cost is obtd. in this way. |
