Patent ID: 7369720

Claim:
An optical device comprising: a semiconductor optical element; and an optical waveguide substrate having a core portion extending in a direction crossing a layer thickness direction and an optical waveguide layer containing a clad portion covering the core portion, an end face of the core portion that is optically coupled to the semiconductor optical element being provided to the side surface of the optical waveguide substrate, wherein the optical waveguide substrate further has first and second substrates disposed so that the principal surfaces thereof are facing each other, the optical waveguide layer is provided between the first substrate and the second substrate, the semiconductor optical element is disposed on a mount area of the side surface of the optical waveguide substrate, the mount area contains the end face of the core portion, a part of the side surface of the first substrate and a part of the side surface of the second substrate, wherein the mount area is contained in the bottom surface of a recess portion formed on the side surface of the optical waveguide substrate.