Patent ID: 6839376

Claim:
A laser light source comprising: a semiconductor light-emitting device for emitting light having two cleaved end facets; an external resonator including a wavelength selector which selects a wavelength of said light; wherein a stripe is formed in said semiconductor light-emitting device so that it is oblique to one end facet, which does not constitute said external resonator, of the two cleaved end facets of said semiconductor light-emitting device; and said one end facet of said semiconductor light-emitting device has a coating which becomes an antireflection coating with respect to the selected wavelength; wherein an optical waveguide device comprising an optical waveguide is coupled to said semiconductor light-emitting device; said wavelength selector has a function of returning the wavelength-selected light to said semiconductor light-emitting device and is disposed on one side of said semiconductor light-emitting device; said optical waveguide device is disposed on the other side of said semiconductor light-emitting device; and said external resonator is constituted by an end facet, on the opposite side from said semiconductor light-emitting device, of said optical waveguide device, and said wavelength selector; wherein said end facet of said optical waveguide device is perpendicular to said optical waveguide.