Patent ID: 7566577

Claim:
A monolithic double wavelength semiconductor laser device including a first semiconductor laser device and a second semiconductor laser device respectively formed on a first conductive-type substrate ( 101 ) and having different emission wavelengths, wherein the monolithic double wavelength semiconductor laser device has an end-face window structure, the first semiconductor laser device has a double hetero structure having, in a stacked manner on the first conductive-type substrate ( 101 ), a first clad layer ( 103 ) of a first conductive type, a first active layer ( 104 ) of a multi-quantum well structure, and a second clad layer ( 105 ) of a second conductive type, the second semiconductor laser device has a double hetero structure having a third clad layer ( 108 ) of the first conductive type, a second active layer ( 109 ) of the multi-quantum well structure, and a fourth clad layer ( 110 ) of the second conductive type, wherein the fourth clad layer ( 110 ) of the second semiconductor laser device has a hydrogen concentration higher than that of the second clad layer ( 105 ) of the first semiconductor laser device.