| 摘要 |
PURPOSE:To improve the connectability of an optical waveguide formed on a substrate to another optical components such as an optical fiber and a laser diode, etc., by stacking auxiliary waveguides on the upper and lover parts of a width expanded waveguide part, and integrating those waveguides. CONSTITUTION:This optical waveguide is the one formed on the substrate 1, and the width of a main waveguide 3 at the input/output terminal part of a light circuit is expanded by tapering. The auxiliary waveguides 5 whose optical axes are parallel with each other and perpendicularly to the substrate 1 are formed on at least either on one side of the upper or lower part of the waveguide at the output terminal part as coming in contact with or approaching closely to the main waveguide 3. The terminating parts of the auxiliary waveguides 5 of the upper and lower parts on the side opposite to the waveguide end face are formed in tapered shape, and the input/output end face of the light circuit is formed integrally with plural waveguides. Therefore, since the partial mode field diameter of the optical waveguide can be expanded in the same substrate with low loss, the connectability to another components such as the optical fiber and the laser diode, etc., can be improved. |
