| 摘要 |
PURPOSE:To improve the sepn. degree between branch paths by providing lens structure near the branching section of an optical waveguide having the refractive index larger than the ambient refractive index and impressing an electric field to the branching section to change the refractive index thereof. CONSTITUTION:A transmission medium having the refractive index larger than the refractive index of the ambient medium 3 is deposited on a substrate to form the optical waveguides 1, 2 crossed to an X shape and the DC electric field is impressed to an electrode pair 4 longitudinally crossing the crossing part to change the refractive index of the transmission medium so that the light wave is totally reflected by the boundary thereof. The light is thus changed over. The medium near the crossing part is built up to form convex lens structures 5, 6. The incident light is focused by lenses 5a, 6a to the central part of the impressed electric field and is made to parallel light by lenses 5b, 6b from which the parallel light are emitted. The scattering of the light wave in the crossing part is thus decreased and the sepn. degree of the branching and changing over is considerably improved. |
