| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser whose outside differential quantum efficiency and kink level are both high. SOLUTION: A semiconductor laser is constituted in such a way that a double heterostructure composed of an active layer 103 and of clad layers 102, 104 which sandwich the active layer 103 and whose refractive index is smaller than that of the active layer is formed on a semiconductor substrate 101, that a stripe-shaped mesa structure is provided on the opposite side of the substrate 101 as viewed from the active layer 103, that a first current block layer 107 whose refractive index is larger than that of the clad layers 102, 104 is provided on both sides of the mesa structure and that a second current block layer 108 whose refractive index is smaller than that of the clad layers is provided further on both outer sides of them. |
