Semiconductor laser device

Claim 1

A semiconductor laser comprising a plurality of semiconductor layers serially disposed on a substrate of a first conductivity type including a first cladding layer of the first conductivity type, a current blocking layer of a second conductivity type opposite the first conductivity type and forming a rectifying junction with said first cladding layer, said current blocking layer including a longitudinal groove extending through said current blocking layer to said first cladding layer, the longitudinal groove having a transverse width along said first cladding layer, a second cladding layer of the first conductivity type disposed on said current blocking layer and in and having the configuration of the groove, a bent active layer disposed on said second cladding layer and having the configuration of the groove and spaced from said first cladding layer at said groove by the thickness of said second cladding layer, a third cladding layer of the second conductivity type, and a contacting layer of the second conductivity type, and first and second electrodes disposed on said substrate and said contacting layer, respectively, wherein a resonant cavity includes a portion of said bent active layer opposite the longitudinal groove, the width of the longitudinal groove at said first cladding layer is less than 2 microns, and the thickness of said second cladding layer at the longitudinal groove is greater than 0.6 micron.