PROBLEM TO BE SOLVED: To improve a laser characteristic.SOLUTION: A semiconductor laser comprises: a first reflection layer in which an exciting light enters and which reflects a discharge light； a second reflection layer provided in a lamination direction of the first reflection layer and reflecting the discharge light； a plurality of active layers having a light emission layer nipped with the first and second reflection layers in the lamination direction, laminated in the lamination direction, and discharging the discharge light by the exciting light, and a first semiconductor layer nipping the light emission layer in the lamination direction； and a second semiconductor layer provided between the first semiconductor layers of the active layer adjacent to the plurality of active layers, and having a second band gap energy larger than a first band gap energy of the first semiconductor layer. The width of the lamination direction of the active layer of the plurality of active layers becomes smaller as approaching to the first reflection layer side.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2020,JPO&INPIT【課題】レーザ特性を向上させることができる。【解決手段】励起光が入射し放出光を反射する第１反射層と、前記第１反射層の積層方向に設けられ前記放出光を反射する第２反射層と、前記積層方向において前記第１反射層および前記第２反射層に挟まれ、前記積層方向に積層され、前記励起光により前記放出光を放出する発光層と、前記積層方向において前記発光層を挟む第１半導体層と、を各々有する複数の活性層と、前記複数の活性層の隣接する活性層の第１半導体層の間に設けられ、前記第１半導体層の第１バンドギャップエネルギーより大きい第２バンドギャップエネルギーを有する第２半導体層と、を備え、前記複数の活性層における活性層の前記積層方向の幅は、前記第１反射層側に行くにしたがい小さくなることを特徴とする半導体レーザ。【選択図】図５
