| 摘要 |
An optical semiconductor device includes an optical semiconductor element and an optical waveguide butt-joined to the optical semiconductor element. The optical semiconductor element has a mesa structure including an active layer and a burying layer coating side faces of the active layer. The optical waveguide has a mesa structure including an optical waveguide layer having a layer structure different from the active layer, and a burying layer coating side faces of the optical waveguide layer. Mesa width of the optical waveguide is narrower than mesa width of the optical semiconductor element. |
