| 摘要 |
A semiconductor optical amplifier includes an n-type semiconductor layer, a p-type semiconductor layer an active layer provided between the n-type semiconductor layer and the p-type semiconductor layer, the active layer transmitting an optical signal and a current-injection part that injects current into the active layer via the n-type semiconductor layer and the p-type semiconductor layer, the active layer including a first active layer that includes AlGaInAs, and a second active layer that includes GaInAsP, the second active layer provided closer to an output side than the first active layer, and the first active layer and the second active layer being butt-jointed. |
