Optical semiconductor device and optical semiconductor integrated circuit

摘要

An integrated optical waveguide (1200) comprising a first optical waveguiding region (1201); a second optical waveguiding region (1202) whose interface surface (1204) with said first optical waveguiding region is inclined with respect to the waveguide direction of said first optical waveguiding region, and having a refractive index different from that of said first optical waveguiding region; and a third optical waveguiding region (1203) whose interface surface with said second optical waveguiding region (1205) is disposed such that a refraction direction through the interface surface with said second optical waveguiding region is in line with the waveguide direction.