| 摘要 |
PURPOSE:To provide the optical waveguide which can be easily produced and can change over a single mode and double mode by the polarization of light. CONSTITUTION:A first core part 2 having the refractive index higher than the refractive index of a substrate 1 to both of ordinary rays and extraordinary rays and second core parts 3a, 3b having the refractive index higher than the refractive index of the substrate 1 only to the extraordinary rays are formed on the substrate 1. The first core part 2 constitutes the single mode waveguide to the ordinary rays and the region where the first core part 2 and the second core parts 3a, 3b are joined constitutes the double mode waveguide to the extraordinary rays. The first core part 2 is formed by a thermal diffusion method and the second core parts 3a, 3b are formed by a proton exchange method or an outward Li2O diffusion method. |
