| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a quartz-based optical waveguide device which is free of sinking of a core in a lower clad layer, slanting, etc., and has extremely small polarization dependency with high yield and good reproducibility. SOLUTION: In a quartz-based optical waveguide comprising a lower clad layer, a core, and an upper layer formed on an Si substrate, the lower clad layer and upper clad layer are formed of BPSG films. A sinking preventive layer is formed of two or more layers with relatively high softening temperature below the core so as to suppress the sinking and tilting of the core owing to softening of the lower clad layer. COPYRIGHT: (C)2004,JPO |
