Semiconductor laser device

Claim 1

A semiconductor laser device comprising: a first electrode; a first conductivity-type GaAs substrate on which said first electrode is disposed; a first conductivity-type Al x Ga.sub.(1-x) As first cladding layer disposed on said substrate opposite said first electrode; a Al y Ga.sub.(1-y) As active layer disposed on said first cladding layer; a second conductivity-type Al x Ga.sub.(1-x) As second cladding layer disposed on said active layer; a GaAs first current blocking layer disposed on said second cladding layer, said first current blocking layer having a groove extending in length in a resonator direction, extending in depth to said second cladding layer, and changing periodically in width transverse to the length and depth; a Al z Ga.sub.(1-z) As second current blocking layer comprising a grating having stripes extending transverse to the resonator direction and disposed on the portions of said first current blocking layer where the groove has the narrower width; a first conductivity-type GaAs third current blocking layer disposed on said second current blocking layer and the portions of said first current blocking layer from which the stripes of said second current blocking layer are absent; a second conductivity-type Al x Ga.sub.(1-x) As third cladding layer filling the groove and disposed on said third current blocking layer; a second conductivity-type GaAs contact layer disposed on said third cladding layer; and a second electrode disposed on said contact layer.