| 摘要 |
PURPOSE:To allow the continuous change of mode conversion efficiency by forming an optical waveguide in the x-axis direction of the crystal axis of a substrate and impressing an electric field in the y-axis direction of the crystal axis. CONSTITUTION:The optical waveguide 2 is formed by a proton exchange method on the LiNbO3 substrate 1 and this direction thereof is aligned to the x-axis direction of the crystal axis. Electrodes 3-1, 3-2 are so provided that the electric field of the direction coinciding with the y-axis of the crystal axis of the substrate 1 can be impressed. A TM-TE mode conversion arises when light is made incident on the optical waveguide 2 in this state. The conversion efficiency is changed by impressing the electric field in the y-axis direction. The reason for the generation of the mode conversion lies conceivably in that a strain is generated in the y-axis direction of the crystal by the proton conversion and that the rotation of the crystal axis is generated by this strain and further, that the strain is changed by the impression of the electric field and that the conversion efficiency is thereby changed. |
