Patent ID: 6335944
Filing Date: 2002-01-01
Classification: H01S

Abstract:
An external-cavity, semiconductor laser module, comprising:a GaAs/AlGaAs-based semiconductor laser configured to produce light at a gain-peak-wavelength &lgr;FP when driven to oscillate in a Fabry-Perot oscillation, &lgr;LIMIT being a shortest wavelength at which the Fabry-Perot oscillation occurs, and exhibit a gain-wavelength characteristic with ripples therein; an optical transmission medium configured to receive the light produced from the semiconductor laser, said optical transmission medium including a Bragg grating having a reflection characteristic centered at a reflection center wavelength &lgr;BG, and a reflection spectrum having a predetermined width at half maximum; and an optical coupler configured to couple the light from the semiconductor laser into the optical transmission medium, wherein a pulling wavelength range, &lgr;PULL, being a range of wavelengths between &lgr;BG and &lgr;LIMIT, a de-tuning range, &lgr;detun, being a range of wavelengths between &lgr;LIMIT and a gain peak wavelength of the gain-wavelength characteristic of the semiconductor laser at a maximum operating current &lgr;(Iop) of the semiconductor laser, &lgr;PULL>&lgr;detun, &lgr;PULLâˆ’&lgr;detun>the predetermined width at half maximum of the reflection spectrum, and &lgr;(Iop) and &lgr;BG being set so that &lgr;BG is at least one of longer than both &lgr;(Iop) and &lgr;FP, and shorter than both &lgr;(Iop) and &lgr;FP.