| 摘要 |
PURPOSE:To obtain an optical device by coating a light waveguide core on a glass substrate with a cladding film followed by annealing in an oxygen-contg. atmosphere to improve level difference coatability to reduce the refractive index difference between the glass substrate and cladding film. CONSTITUTION:A core film b is first formed by sputtering technique on a glass substrate a using, as target, a material consisting mainly of SiO2 and containing a dopant such as GeO2 or TiO2 followed by annealing in an oxygen-contg. atmosphere at 600-1300 deg.C. Then, an unnecessary portion of the core film b is eliminated by photoetching to form a light waveguide core film b. Subsequently, a cladding film c is formed on the substrate a by CVD technique using, as target, a material having the same component as that of the substrate a followed by annealing in an oxygen-contg. atmosphere at 600-1300 deg.C. |
