| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser in which the oscillation wavelength can be made longer than a conventional one, and the wavelength sweep width can be widened.SOLUTION: A semiconductor laser includes an InP substrate, a distortion relaxation layer laminated on the InP substrate and composed of InAlAs or InGaAlAs, a lower clad layer laminated on the distortion relaxation layer, a quantum well layer including an active layer, and an upper clad layer laminated on the quantum well layer. The distortion relaxation layer has a thickness exceeding the critical film thickness, and a lattice constant larger than that of the InP substrate, and the lower clad layer and upper clad layer are composed of InAlAs or InGaAlAs. |
