SEMICONDUCTOR LASER MODULE

摘要

A semiconductor laser module (1) of external cavity type in which a GaAs/AlGaAs semiconductor laser (2) having ripples in the gain wavelength characteristic and an optical transmission medium (3) having a Bragg grating (3c) are optically coupled together by optical coupling means (4). The gain peak wavelength ( lambda (Ith)) of when the semiconductor laser module is driven by a threshold current (Ith) is shorter than the reflection center wavelength ( lambda BG) of the Bragg grating; the gain peak wavelength ( lambda (Iop)) of the semiconductor laser in the case of the maximum operating current (Iop) is longer than the gain peak wavelength ( lambda (Ith)). The detuning width ( lambda detun) of the semiconductor laser is smaller than the pull-in width ( lambda PULL) of the semiconductor laser, and the difference (= lambda PULL- lambda detun) is larger than the full width at half maximum of the reflection spectrum of the Bragg grating. The gain peak wavelength ( lambda (Ith)) is longer than the limit value ( lambda LIMIT).