Distributed feedback semiconductor laser device and multi-wavelength laser array

摘要

A distributed feedback semiconductor laser device including an active layer, a diffraction grating disposed in a vicinity of the active layer and having a substantially uniform space period and a distributed feedback function, and a functional layer disposed in a vicinity of the diffraction grating and the active layer and having a function of controlling a refractive index of the active layer, whereby the functional layer controls a lasing wavelength of the active layer. 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.