OPTICAL SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide an optical semiconductor device for eliminating electron carrier leakage current on a hetero interface on both side faces to prevent saturation of a light output in an InGaAlAsP-based multiple quantum-well-buried hetero structure. SOLUTION: A conductive band end position of an n-InGaAlAsP light confinement layer 2 and a (In0.91Ga0.09)0.82Al0.18AszP1-zbarrier layer 5 of the optical semiconductor device is made to be at +50meV if higher than InP so that no electron carrier leakage current flows to a hetero junction notch of a p-InP block layer 11 in contact with both side faces. In addition, to make the conductive band end of a well deep, a compressive distortion In0.91Ga0.09AszP1-zwell layer 4 is employed as the well. COPYRIGHT: (C)2008,JPO&INPIT