Patent ID: 7593442

Claim:
A semiconductor laser device comprising: a first conductive type (n) substrate ( 101 ); an active layer ( 106 ) provided on the first conductive type substrate; a second conductive type (p) semiconductor layer group ( 107 - 114 ), which is provided on the active layer ( 106 ) and has a stripe-shaped ridge portion ( 130 ) in an upper portion; the stripe-shaped ridge portion including an upper cladding layer ( 112 ), a first contact layer ( 113 ), and a second contact layer ( 114 ); a semiconductor layer ( 111 ), included in the second conductive type semiconductor layer group ( 107 - 114 ), where the upper cladding layer ( 112 ) is provided on a first portion of the semiconductor layer ( 111 ) and the second contact layer ( 114 ) is provided above the first portion of the semiconductor layer ( 111 ); and an electrode ( 115 ), which is put in contact with a side surface of the upper cladding layer ( 112 ), a side surface of the first contact layer ( 113 ), and a side surface and an upper surface of the second contact layer ( 114 ), where part of the electrode is provided on a second portion of the semiconductor layer ( 111 ), wherein the electrode comprising a layer made of Ag on a side on which the electrode is put in contact with the second conductive type semiconductor layer group.