Patent ID: 7295587
Filing Date: 2007-11-13
Classification: B82Y,H01S

Abstract:
1. A semiconductor laser element comprising: a semiconductor substrate of a first conductivity type; a lower cladding layer of the first conductivity type formed above a surface of said semiconductor substrate; an optical guide layer formed above said lower cladding layer; a quantum-well active layer formed above said optical guide layer; an upper cladding layer of a second conductivity type formed above said quantum-well active layer; a contact layer of the second conductivity type formed above said upper cladding layer; a first electrode of the first conductivity type formed below said lower cladding layer; and a second electrode of the second conductivity type formed on said contact layer; wherein said optical guide layer has a first bandgap smaller than a second bandgap which said lower cladding layer has, and the whole or a portion of the optical guide layer contains a dopant so as to realize a carrier concentration of 3.0×10