| 摘要 |
PROBLEM TO BE SOLVED: To emit light of a wavelength band required for optical communication by a method wherein at least either of quantum well layers and barrier layers are respectively constituted of a GaAlInAs layer and the composition of the quantum well layers is set into a composition of a grating constant larger than that of an InP substrate. SOLUTION: An N-type buffer layer 12, an optical confinement layer 18, an active layer 17, an optical confinement layer 19, a P-type InP clad layer 13, a P-type GaInAsP cap layer 14, an N-type electrode 15 and a P-type electrode 16 are formed on an N-type InP substrate 11 to constitute the main part of a quantum well semiconductor laser element. Quantum well layers 20 and barrier layers 21 are alternately laminated as the layer 17 to constitute the layer 17. At least either of the layers 20 and the layers 21 are respectively constituted of an AlGaInAs layer, the layers 20 are respectively constituted of a GaAlInAs layer and. the layers 21 are respectively constituted of a GaInAsP layer. Moreover, it is also possible that the layers 20 and the layers 21 are respectively constituted of a GaInAsP layer and a GaAlInAs layer. The composition of the layers 20 are set so as to become a composition of a grating constant larger than that of the InP substarte. |
