| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser that can enhance the injection efficiency of electrons into an active layer having a quantum well structure.SOLUTION: A semiconductor laser has an active layer 20 containing a single or plural well layers, an n-side optical guide layer 12 and an n-type clad layer 11 which are formed at the electron injection side of the active layer 20, a p-side optical guide layer 17 and a p-type clad layer 16 which are formed at the hole injection side of the active layer 20, and an electron injection layer 21 having a multiquantum well structure provided between the active layer 20 and the n-side optical guide layer 12. Electrons are injected into an excitation level Le in the well layer of the active layer 20 through a mini band MB in the injection layer 21. A level adjusting layer 22 for transporting electrons is provided between the electron injection layer 21 and the n-side optical guide layer 12. The level adjusting layer 22 is configured so that the lowest energy position of electrons in the layer is within the energy range of the mini band MB. |
