Patent ID: 7103081

Claim:
A semiconductor laser having a distributed feedback grating for emitting light with plural Fabry-Perot modes having a first gain spectrum and a Bragg grating mode having a second gain spectrum, the laser comprising: an active region made of a semiconductor material; a Bragg grating for defining the Bragg grating mode; a light-reflecting surface for reflecting light generated in the active region; and a light-emitting surface with an anti-reflective coating thereon, the light-emitting surface with the anti-reflective coating having a reflectivity, the light-emitting surface and the light-reflecting surface forming a Fabry-Perot resonator combined with the active region for defining the plural Fabry-Perot modes, wherein the reflectivity of the light-emitting surface has a minimum at a wavelength where the first gain spectrum of the Fabry-Perot modes becomes a maximum at temperatures where the maximum of the first gain spectrum of the Fabry-Perot modes is greater than the maximum of the second gain spectrum of the Bragg grating mode.