Semiconductor optical function device

1. A semiconductor optical function device, comprising:

a semiconductor substrate having a substrate edge surface at an end thereof in a longitudinal direction;

an optical waveguide formed on the semiconductor substrate so as to extend in the longitudinal direction;

a non-waveguide region formed on the semiconductor substrate between the optical waveguide and the substrate edge surface; and

an insulation region disposed around the optical waveguide and having a semiconductor interface surface that is an interface between the insulation region and the semiconductor substrate, and is formed at an end thereof in the longitudinal direction so as to be opposite of the substrate edge surface, said semiconductor interface surface extending outwardly away from the optical waveguide and being inclined relative to the substrate edge surface by a specific angle,

wherein said optical waveguide has a center axis extending in a direction inclined relative to the substrate edge surface, and

said semiconductor interface surface is situated away from the substrate edge surface by a distance increasing as the semiconductor interface surface extends away from the optical waveguide.

2. The semiconductor optical function device according to claim 1 , wherein said optical waveguide is arranged so that light is completely reflected on the substrate edge surface.

3. The semiconductor optical function device according to claim 1 , wherein said optical waveguide includes a bend portion at an end portion thereof.

4. The semiconductor optical function device according to claim 1 , further comprising a semiconductor optical function element formed on the optical waveguide.