US 5,675,601 A · Semiconductor laser device

Abstract

A semiconductor laser device includes, on a first conductivity type GaAs substrate, successively, a first conductivity type GaAs buffer layer, a first conductivity type Al.sub.s Ga.sub.1-s As (0<s<1) cladding layer, a quantum well active layer having a structure that can produce an oscillation wavelength of 0.9.about.1.2 .mu.m and including a well layer comprising In.sub.x Ga.sub.1-x As (0<x<1) and a barrier layer comprising Al.sub.y Ga.sub.1-y As (0<y<s), a second conductivity type Al.sub.t Ga.sub.1-t As (1<t<y) upper cladding layer, a second conductivity type GaAs contact layer, and a multiple reflection film layer alternatingly laminating first and second semiconductor materials which have the same conductivity type as the adjacent semiconductor materials and have the different refractive indices in number of layers, first and second electrodes, and a pair of laser resonator facets perpendicular to the active layer and the multiple reflection film layer. Therefore, a semiconductor laser device in which generation of large mode hops is suppressed, the generation of kinks is reduced, and stable and high power output laser beams are produced is realized.

Claims26

Dependent claims

A semiconductor laser device comprising:

a first conductivity type GaAs substrate having opposed front and rear surfaces;
a first conductivity type GaAs buffer layer disposed on the front surface of the first conductivity type GaAs substrate;
a first conductivity type Al.sub.s Ga.sub.1-s As (0<s<1) cladding layer disposed on the first conductivity type GaAs buffer layer;
a quantum well active layer having a structure that can oscillate at a wavelength of 0.9.about.1.2 .mu.m and including a well layer comprising In.sub.x Ga.sub.1-x As (0<x<1) and a barrier layer comprising Al.sub.y Ga.sub.1-y As (0<y<s), disposed on the first cladding layer;
a second conductivity type Al.sub.t Ga.sub.1-t As (y<t<1) cladding layer disposed on the active layer;
a second conductivity type GaAs contact layer disposed on the second conductivity type cladding layer;
a multiple reflection film layer, including alternatingly laminated, layers of first and second semiconductor materials which have the same conductivity type as adjacent semiconductor layers and have different refractive indexes disposed parallel to the active layer but not in contact with the active layer, at a position relative to the active layer;
a first electrode disposed on the rear surface of the semiconductor substrate;
a second electrode disposed on the second conductivity type contact layer;
and
a pair of laser resonator facets perpendicular to the active layer and the multiple reflection film layer.

8 more elements

A semiconductor laser device comprising:

a first conductivity type GaAs substrate having opposed front and rear surfaces;
a first conductivity type GaAs buffer layer disposed on the front surface of the first conductivity type GaAs substrate;
a first conductivity type Al.sub.s Ga.sub.1-s As (0<s<1) cladding layer disposed on the first conductivity type GaAs buffer layer;
a quantum well active layer having a structure that can produce an oscillation wavelength of 0.9.about.1.2 .mu.m and including a well layer comprising In.sub.x Ga.sub.1-x As (0<x<1) and a barrier layer comprising Al.sub.y Ga.sub.1-y As (0<y<s), disposed on the first conductivity type cladding layer;
a second conductivity type Al.sub.t Ga.sub.1-t As (y<t<1) cladding layer disposed on the active layer;
a second conductivity type contact layer disposed on the second conductivity type cladding layer;
a first electrode disposed on the rear surface of the semiconductor substrate;
a second electrode disposed on the second conductivity type contact layer;
and
a pair of resonator facets perpendicular to the active layer, wherein
one of said semiconductor substrate, said buffer layer, and said contact layer comprising a material absorbing laser light generated in the active layer and the other layers being GaAs.

8 more elements

A semiconductor laser device comprising:

a first conductivity type GaAs substrate having opposed front and rear surfaces;
a first conductivity type GaAs buffer layer disposed on the front surface of the first conductivity type GaAs substrate;
a first conductivity type Al.sub.s Ga.sub.1-s As (0<s<1) cladding layer disposed on the first conductivity type GaAs buffer layer;
a quantum well active layer having a structure that can produce an oscillation wavelength of 0.9.about.1.2 .mu.m and including a well layer comprising In.sub.x Ga.sub.1-x As (0<x<1) and a barrier layer comprising Al.sub.y Ga.sub.1-y As (0<y<s), disposed on the first conductivity type cladding layer;
a second conductivity type Al.sub.t Ga.sub.1-t As (y<t<1) cladding layer disposed on the active layer;
a second conductivity type GaAs contact layer disposed on the second conductivity type cladding layer;
a critical film thickness layer laminated structure alternatingly laminating a layer having a first strain relative to the substrate, having a thickness less than a critical film thickness, and comprising a material absorbing laser light, and a layer having a second strain relative to the substrate, smaller than the first strain, not in contact with the active layer, and having the same conductivity type as adjacent layers;
a first electrode disposed on the rear surface of the GaAs substrate;
a second electrode disposed on the upper surface of the contact layer;
and
a pair of resonator facets perpendicular to the active layer.

8 more elements

A semiconductor laser device comprising:

a first conductivity type GaAs substrate having opposed front and rear surfaces;
a first conductivity type GaAs buffer layer disposed on the front surface of the first conductivity type GaAs substrate;
a first conductivity type Al.sub.s Ga.sub.1-s As (0<s<1) cladding layer disposed on the first conductivity type GaAs buffer layer;
a quantum well active layer having a structure that can produce an oscillation wavelength of 0.9.about.1.2 .mu.m and including a well layer comprising In.sub.x Ga.sub.1-x As (0<x<1) and a barrier layer comprising Al.sub.y Ga.sub.1-y As (0<y<s), disposed on the first conductivity type cladding layer;
a second conductivity type cladding layer comprising In.sub.r Ga.sub.1-r P having an In composition ratio r so as to have the same lattice constant as that of the first conductivity type GaAs substrate and having a thickness larger than 4 .mu.m on a light emitting region of the active layer, disposed on the quantum well active layer;
a second conductivity type GaAs contact layer disposed on the second conductivity type cladding layer;
a first electrode disposed on the rear surface of the GaAs substrate;
a second electrode disposed on the second conductivity type contact layer;
and
a pair of resonator facets perpendicular to the active layer.

7 more elements

Dependencies are inferred from the claim text.

Semiconductor laser device

Life of this patent

Semiconductor laser device

Life of this patent

Abstract

Claims26