A semiconductor laser device.

摘要

A semiconductor laser device comprises a GaAlAs first cladding layer (2), a Ga1-xAlxAs (0≦×≦0.4) active layer (3) for laser oscillation, an In1-yGayP1-zAsz (z=2.04y-1.04, and (0≦z≦1)optical guiding layer (4) with a diffraction grating (44) thereon, a GaAlAs buffer layer (9) disposed between said active layer (3) and said optical guiding layer (4), and a GaAlAs second cladding layer (5), the width of the forbidden band of said buffer layer (9) being greater than that of said active layer (3) and smaller than that of said optical guiding layer (4).