| 摘要 |
PURPOSE:To reduce light absorption in a waveguide, and realize stable laser oscillation at a low threshold value, regarding an optical semiconductor device applied to the light source for optical communication, optical disc apparatus, and optical interconnection. CONSTITUTION:A semiconductor device contains a stripe type quantum well structure layer 6, and a first and a second clad layers 3 which sandwich the quantum well structure layer 6, which is constituted by the following. A quantum well is formed from a gain region A which emits light to a mode conversion region B which does not emit but guides light. In the mode conversion region B, the film thickness is reduced in accordance with the distance further from the gain region A, without changing the number of layers. The film thickness at the incident end of the mode conversion region B is twice or more as compared with that of output end. |
