Optical waveguide device, its manufacture method, laser module and optical transmission system

摘要

A first optical waveguide of a convex shape is formed over a substrate. A second optical waveguide of a convex shape is formed over the substrate. A multimode interference waveguide of a convex shape is formed over the substrate for optically coupling the first optical waveguide to the second optical waveguide. Either side of the first optical waveguide is filled with a filling material, but either side of the second optical waveguide is not filled with the filling material.