| 摘要 |
PURPOSE: To realize an optical waveguide consisting of a quartz material, capable of being formed by a low-temp. process and extremely low in loss. CONSTITUTION: A lower clad layer 2 and a core layer 3a having a lower refractive index than the material of the clad layer are formed on a substrate 1, a striped core 3b is formed by etching, then the substrate 1 is subjected to reflowing at a temp. higher than the reflowing temp. of the material of the core 3b, and hence the refractive index of the material of the core 3b is increased. An upper clad layer 4 is then formed on the core 3b. |
