External cavity light emitting device

Light source 1, an active layer 3 for oscillating a semiconductor laser beam. Grating element 2B is a semiconductor optical waveguide 7 laser light has an emission portion 7b for emitting outgoing light of a desired wavelength and the incident surface 7a incident, and the optical waveguide of the plurality of cycles to each other formed in the 7 different Bragg grating G1 It comprises G2, G3. When a half the reflectivity R .FIELD 6