InGaAsP or InGaAs semiconductor laser element in which near-edge portion of active layer is substituted with GaAs optical waveguide layer having greater bandgap than active layer

摘要

In a semiconductor laser element, a lower cladding layer of a first conductive type, a GaAs first optical waveguide layer of the first conductive type or an undoped type, an InGaAsP or InGaAs compressive-strain active layer, a GaAs second optical waveguide layer of a second conductive type or an undoped type, and an upper cladding portion are formed on a GaAs substrate of the first conductive type. The active layer is not formed in at least one vicinity of at least one end facet, and the space in the at least one vicinity of the at least one end facet is filled with a third optical waveguide layer of the second conductive type or an undoped type, where the bandgaps of the first, second, and third second optical waveguide layers are greater than the bandgap of the active layer.