Semiconductor laser device.

摘要

A semiconductor laser device comprises a substrate (1) formed of elements of the III-IV groups and having one conductivity type, a lower clad layer (3) formed on the substrate (1) and having the same conductivity type as that of the substrate (1), and an upper clad layer (5) formed on the lower clad layer (3) and having a conductivity type opposite to that of the lower clad layer (3). A waveguide layer having a large refractive index is formed within the lower clad layer (3) by decreasing the band gap of the upper clad layer (5). The light generated in an activation layer (4) is guided to the lower clad layer (3), so as to suppress adverse effects which the upper clad layer (5) may have on element characteristics.