| 摘要 |
PURPOSE:To freely control the double refraction by forming an optical waveguide with a substrate, a quartz.glass clad layer formed on the substrate, a quartz glass core path formed in the clad layer, and a stress applying part which is provided near the core path and in the clad layer and applies a stress to the core path. CONSTITUTION:A quartz optical waveguide film consisting of a lower clad layer 31 and a core layer 32 is accumulated on a quartz glass substrate 21, and an unnecessary part of the core layer 32 is removed by reactive ion etching to form a ridge-shaped core path 2. An intermediate clad layer 33 is so deposited that the core path 2 is buried, and an a-Si layer is formed on the upper face of the intermediate clad layer 33, and an unnecessary part is removed by etching to leave stress applying parts 4a and 4b, and an upper clad layer 34 is so deposited that stress applying parts 4a and 4b are buried, and a-Si is transformed to polysilicon by heat treatment at a high temperature, and stress double refraction is caused in the process of cooling to a room temperature. Thus, the double refraction property of the optical waveguide is precisely controlled by positions and the shape of stress applying parts. |
