| 摘要 |
PURPOSE:To enable always stable operation without generating a malfunction by forming LiNbO3 to the state projecting from the surface of two proximate light guides in the region between said light guides. CONSTITUTION:The pattern of titanium 5 corresponding to the pattern of a desired optical directional coupler 2 is first formed on an LiNbO3 substrate 1. The Ti 5 is then thermally diffused by a high-temp. treatment into the LiNbO3 substrate 1 to form the optical directional coupler 2. A metal or dielectric or the like as a mask material 6 is then deposited to the region of the LiNbO3 substrate 1 where the projecting part 3 of the LiNbO3 is to be formed. The part of the LiNbO3 substrate 1 in the region where the projecting part 3 of the LiNbO3 is to be formed is etched. Finally, electrodes 4 are installed on the optical directional coupler 2. The always stable operation is thereby obtd. without generating the malfunction. |
