External resonator-type light emitting device

摘要

An external resonator type light emitting system includes a light source oscillating a semiconductor laser light and a grating device providing an external resonator with the light source. The light source includes an active layer oscillating the semiconductor laser light. The grating device includes an optical waveguide having an incident face to which the semiconductor laser is incident and an emitting face of emitting an emitting light of a desired wavelength, a Bragg grating formed in the optical waveguide, and a propagating portion provided between the incident face and the Bragg grating. Formulas (1) to (4) are satisfied.

主权项

1. An external resonator type light emitting system comprising a light source oscillating a semiconductor laser light and a grating device providing an external resonator with said light source;
wherein said light source comprises an active layer oscillating said semiconductor laser light; wherein said grating device comprises an optical waveguide comprising an incident face to which said semiconductor laser light is incident and an emitting face of emitting an emitting light of single mode and having a desired wavelength, a Bragg grating formed in said optical waveguide, and a propagating portion provided between said incident face and said Bragg grating; wherein said optical waveguide comprises a core; wherein a cross section of said core is of a convex shape; and wherein the following formulas (1) to (5) are satisfied:
(1) ΔλG≧0.8nm(2) Lb≦500 μm(3) La≦500 μm(4) nb≧1.8nm(5)|(dλG/dT)−(dλTM/dT)|≦0.03 nm / ° C.; wherein ΔλG represents a full width at half maximum of a peak of a Bragg reflectance in said formula (1); Lb represents a length of said Bragg grating in said formula (2); La represents a length of said active layer in said formula (3); and nb represents a refractive index of a material forming said Bragg grating in said formula (4); dλG/dT represents a temperature coefficient of a Bragg wavelength in said formula (5); and dλTM/dT represents a temperature coefficient of a wavelength satisfying a phase condition of an external resonator laser in said formula (5).