Semiconductor laser

摘要

A semiconductor laser comprising a triple-layered structure composed of an active layer for laser oscillation and a pair of optical guiding layers sandwiching said active layer therebetween, wherein the refractive index of each of said optical guiding layers is smaller than that of said active layer, and the bandgap of each of said optical guiding layers is greater than that of said active layer, and moreover diffraction gratings with different pitches are positioned on the outer side of each of said optical guiding layers.