Patent ID: 7459719
Filing Date: 2008-12-02
Classification: B82Y,H01S

Abstract:
1. An optical semiconductor device comprising: an active layer having a quantum well structure including alternately stacked well layers and barrier layers, wherein a bandgap of said barrier layers is larger than a bandgap of said well layers, wherein each of said well layers and said barrier layers has a constant band gap, said active layer is made of a group III-V compound semiconductor, wherein a content of each of group III elements and group V elements is uniform in each of said well layers regardless of a position therein, wherein a content of each of group III elements and group V elements is varied along the thickness direction in each of said barrier layers, each of said well layers is made of AlGaInAs and each of said barrier layers is made of AlGaAsP, wherein contents of said AlGaAsP are modulated in each of said barrier layers, Ga and P contents in each of said barrier layers are increased in a center portion thereof in the thickness direction and reduced in a portion thereof in the vicinity of said well layer.