Distributed feedback semiconductor laser device and multi-wavelength laser array

摘要

A distributed feedback semiconductor laser device including an active layer (18), a diffraction grating disposed in a vicinity of the active layer (18) and having a substantially uniform space period and a distributed feedback function, and a functional layer (28a and 32) disposed in a vicinity of the diffraction grating and the active layer (18) and having a function of controlling a refractive index of the active layer (18), whereby the functional layer controls a lasing wavelength of the active layer (18). The functional layer of controlling the refractive index of the distributed feedback semiconductor laser device can generate a plurality of the lasing wavelengths different among one another and easily controllable.