Low operating current and low noise semiconductor laser device for optical disk memories

A semiconductor laser device comprising a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide and In.sub.0.5 Ga.sub.0.5 P second light guide layer, an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on said second light guide layer and provided with a stripe-like window and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of said certain conduction type formed over the areas including said stripe-like window where said current blocking layer is not being formed, all successively formed one upon another on at least one principal plane of an active layer having a quantum well structure, wherein relations of Z>Y1 and Z>Y3 are established among Y1, Y3 and Z that define the AlAs mole-fractions.

A semiconductor laser device comprising a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide and InGaAsP second light guide layer, an opposite conduction type GA.sub.1-Z Al.sub.Z As current blocking layer formed on said second light guide layer and provided with a stripe-like window and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of said certain conduction type formed over the areas including said stripe-like window where said current blocking layer is not being formed, all successively formed one upon another on at least one principal plane of an active layer having a quantum well structure, wherein relations of Z>Y3 and Z>Y1 are established among Y1, Y3 and Z that define the AlAs mole-fractions.

A semiconductor laser device comprising a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide and In.sub.0.5 (GaAl).sub.0.5 P second light guide layer, an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on said second light guide layer and provided with a stripe-like window and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of said certain conduction type formed over the areas including said stripe-like window where said current blocking layer is not being formed, all successively formed one upon another on at least one principal plane of an active layer having a quantum well structure, wherein relations of Z>Y3 and Z>Y1 are established among Y1, Y3 and Z that define the AlAs mole-fractions.

A semiconductor laser device comprising a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer and In.sub.0.5 Ga.sub.0.5 P second light guide layer, an opposite conduction type GA.sub.1-Z Al.sub.Z As current blocking layer formed on said second light guide layer and provided with a stripe-like window and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of said certain conduction type formed over the areas including said stripe-like window where said current blocking layer is not being formed, all successively formed one upon another on at least one principal plane of an active layer comprised of a Ga.sub.1-X Al.sub.X As layer, wherein relations of Z>Y3>X.gtoreq.0 and Z>Y1 are established among X, Y1, Y3 and Z that define the AlAs mole-fractions.

A semiconductor laser device comprising a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer and InGaAsP second light guide layer, an opposite conduction type GA.sub.1-Z Al.sub.Z As current blocking layer formed on said second light guide layer and provided with a stripe-like window and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of said certain conduction type formed over the areas including said stripe-like window where said current blocking layer is not being formed, all successively formed one upon another on at least one principal plane of an active layer comprised of a Ga.sub.1-X Al.sub.X As layer, wherein relations of Z>Y3>X.gtoreq.0 and Z>Y1 is established among X, Y1, Y3 and Z that define the AlAs mole-fractions.