| 摘要 |
PURPOSE:To increase the translation rate of light power by doping a clad part between close parts of two optical waveguides with a material which varies the refractive index. CONSTITUTION:The optical coupler has at least two optical waveguides 3a and 3b formed closely to each other and the clad part between the optical waveguides 3a and 3b is doped with the material, e.g. an MgO pattern 5 which varies the refractive index. The optical switch is constituted by forming electrodes 7a and 7b on the optical coupler where the clad part between the close parts of the optical waveguides 3a and 3b is doped with the material varying the refractive index. Therefore, the refractive index of the clad part between the close part of the optical waveguides 3a and 3b varies and the coefficient of coupling between the optical waveguides 3a and 3b varies. Consequently, the optical coupler which has complete coupling length set corresponding to the coupling length between the optical waveguides 3a and 3b and a high translation rate of light power is obtained, and the optical switch having superior characteristics of an extinction ratio, etc., is obtained. |
