SEMICONDUCTOR LASER DEVICE, AND SEMICONDUCTOR LASER MODULE AND RAMAN AMPLIFIER USING IT

摘要

PROBLEM TO BE SOLVED: To obtain a semiconductor laser device that is suited for a light source for a Raman amplifier that is stable and can obtain a high gain, and to provide a semiconductor laser module, and the Raman amplifier using the semiconductor laser module. SOLUTION: A diffraction grating is provided near an active layer formed between a first reflection film that is provided ion the emission end face of a laser beam and a second reflection film that is provided on the reflection end face of the laser beam, and a laser beam including at least two oscillation vertical modes 31-33 within a half-value widthΔλh of an oscillation wavelength spectral 30 is outputted by combining oscillation parameters including the length of a resonator formed by the active layer and the wavelength selection characteristics of the diffraction grating. In this case, the diffraction grating may be set to a chirped grating for achieving periodical fluctuation, or may be provided at one portion.