Patent ID: 7274721

Claim:
A monolithic multi-wavelength laser device comprising: a substrate; a first-wavelength lasing part having a ridge portion; and a second-wavelength lasing part having a ridge portion, wherein each of said first-wavelength lasing part and said second-wavelength lasing part comprises: a current blocking layer comprising a semiconductor thin film and covering a side surface of a corresponding ridge portion and bending to extend away from the corresponding ridge portion along a plane on which the corresponding ridge portion stands, and an insulation layer comprising an insulating dielectric thin film, covering said current blocking layer and made of a material having a lower refractive index than said current blocking layer, a surface portion of said insulation layer has an oxygen concentration and/or a nitrogen concentration in the range of 0 to 0.00 1, and a thickness of said insulation layer is in the range of 0.05 μm to 0.2 μm, and the thin film of the current blocking layer contains at least one material selected from a group consisting of GaAs, α-Si and Ge.