Abstract: A semiconductor laser element comprising: a clad layer of a first conductivity type; an active layer; a first clad layer of a second conductivity type; a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side; a dielectric film formed on ridge sides other than a top portion of the ridge; and a metal electrode layer that covers the ridge, wherein the width of the bottom of the cap layer and the width of the top surface of the second clad layer are approximately equal.

Abstract: A semiconductor laser element comprising: a clad layer of a first conductivity type; an active layer; a first clad layer of a second conductivity type; a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side; a dielectric film formed on ridge sides other than a top portion of the ridge; and a metal electrode layer that covers the ridge, wherein the width of the bottom of the cap layer and the width of the top surface of the second clad layer are approximately equal.

Abstract: A method for manufacturing a semiconductor laser device, comprising the steps of: forming an electrode pattern on an upper surface of a semiconductor wafer stacked at least a light emission layer; cutting the resultant semiconductor wafer for predetermined width to yield a plurality of semiconductor bars; and sectioning the semiconductor bars into a desired size to form semiconductor laser devices having a pair of cleavage surfaces which are parallel to a chip-width direction and distant from each other by a predetermined resonator length, wherein the electrode pattern formed in the step of forming an electrode pattern is continuous at least in a resonator-length direction.

Abstract: The present invention provides a method for producing a semiconductor laser device having at least a light emitting section, a cap layer and an electrode successively formed on a semiconductor substrate, the light emitting section including a light emitting layer located approximately in a middle of a thickness of the device. The method includes the step of growing the light emitting section and the cap layer using a vapor phase epitaxy method, wherein a growth rate of the cap layer is greater than a growth rate of the light emitting section.

Abstract: A vapor growth apparatus and a vapor growth method is capable of growing a compound semiconductor layer having an evenness and an interfacial sharpness in units of atomic layers with a good productivity. A growth chamber has a cylindrical portion and an end plate which closes an upstream end of the cylindrical portion. The end plate is provided with a cation gas material supply inlet and an anion material gas supply inlet, while an exhaust device is provided on the downstream side of the cylindrical portion. A substrate holder having a substrate support surface is provided in the cylinder portion. A gas separating member separates flow paths of material gases from each other, thereby forming on the substrate support surface a plurality of material gas supply areas to which the material gases are independently supplied. A drive device rotates the substrate holder with a substrate set on the substrate support surface thereof around the center line of the cylindrical portion.

Abstract: A semiconductor laser device which can effectively confine electrons and positive holes is disclosed. The semiconductor laser device includes a semiconductor substrate of a first conductivity type, a current blocking layer of a second conductivity type, a first semiconductor layer of the first conductivity type made of a III-V group compound semiconductor, an active layer made of a III-V group compound semiconductor, and a second semiconductor layer. The semiconductor substrate has a ridge-type mesa having (n11)A planes. The current blocking layer is formed on the semiconductor substrate other than the top face of the mesa. The first semiconductor layer is formed on the entire surface of the current blocking layer and on the top face of the mesa. The active layer is formed on the first semiconductor layer. The second semiconductor layer is formed on the active layer.

Abstract: A semiconductor laser device is disclosed which emits laser light from a facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on the facet, wherein a film containing sulfur is provided between the facet and the protective film.

Abstract: A semiconductor laser device is disclosed which emits laser light from a facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an AlGaAs active layer for laser oscillation, and a protective film formed on the facet, wherein a film containing sulfur is provided between the facet and the protective film.

Abstract: A semiconductor laser device is disclosed which emits laser light from an end facet. The semiconductor laser device comprises a multi-layered structure formed on a semiconductor substrate, the multi-layered structure having an active layer for laser oscillation, and a pair of cleavage planes on the side of the multi-layered structure, wherein a graded-band-gap layer is formed on at least one of the cleavage planes, the graded-band-gap layer having a forbidden band gap which increases gradually with an increase in the distance from the cleavage plane, and the surface of the graded-band-gap layer constituting the end facet.

Abstract: A method for the formation of a diffraction grating on a substrate using a holographic technique and an etching technique, wherein the periodicity of the pattern of the diffraction grating can be changed at will by a change of the light-path length of one of the two light fluxes from a holographic exposing system.

Abstract: A semiconductor laser device comprising an active layer that constitutes a laser-oscillating resonator, and an inner-striped channel in the resonating direction, light from the active layer being absorbed at both edges of the striped channel, resulting in an optical waveguide within the active layer, wherein the amount of light to be absorbed at both edges of the striped channel in the vicinity of at least one of the light-emitting facets is smaller than that to be absorbed at both edges of the striped channel inside of the light-emitting facets.

Abstract: A semiconductor laser element of the present invention provides a double hetero junction structure having two clad layers and an active layer formed between the two clad layers. High resistance regions are formed vertically to the light propagating direction at almost the same interval as the light wavelength in at least one of the two clad layers. The high resistance regions form a periodic current blocking structure so the semiconductor laser element may oscillate in a single longitudinal mode even in a non-steady state operation.

Abstract: A semiconductor laser device comprises a substrate and a multi-layered crystal structure with an active layer for laser-oscillating operation, the multi-layered crystal structure being disposed on the substrate and having a striped channel area through which current is supplied to the active layer and a light-absorbing area positioned outside of the channeled area by which a difference between the amount of light to be absorbed inside of the channeled area and the amount of light to be absorbed outside of the channeled area is created, which causes a difference in the effective refractive index of the active layer, resulting in an optical waveguide in the active layer, wherein the active layer is flat and uniform and the width of the portion of the channel area in the vicinity of at least one facet is wider than that of the remaining portion of the channel area.

Abstract: A semiconductor laser device comprising a semiconductor substrate, an active layer having a refractive index greater than that of said substrate and having an energy gap smaller than that of said substrate, and a cladding layer having a conductivity type different from that of said substrate, in that order, resulting in a double-heterostructure, wherein two parallel grooves with a given distance therebetween are disposed in the double-heterostructure so as to reach said substrate and a first burying layer having the same conductivity type as said substrate, a second burying layer having a conductivity type different from that of said substrate and a third burying layer having the same conductivity type as said substrate are disposed outside of the two grooves in that order, and moreover a semiconductor layer with the flat surface having a conductivity type different from that of said substrate is disposed over the third burying layer and the area positioned between the two parallel grooves.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operating area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operation area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A V-channeled substrate inner strip (VSIS) semiconductor laser includes a p-Ga.sub.1-31 y Al.sub.y As active layer sandwiched between a P-Ga.sub.1-x Al.sub.x As first cladding layer and an n-Ga.sub.1-x Al.sub.x As second cladding layer. The AlAs mole fraction x of the first and second cladding layers is selected between about 0.45 and 0.52 in order to minimize the mode competition noise at an operating temperature. In a preferred form, the cavity length is longer than 300 .mu.m so as to minimize the occurrence of the mode competition noise at the operating temperature. Furthermore, the reflectivity R.sub.1 of the front facet and the reflectivity R.sub.2 of the rear facet are selected to satisfy the condition 0.1.ltoreq.ln(1/R.sub.1 .multidot.R.sub.2).ltoreq.1.

Abstract: An integrated semiconductor laser device comprising a plurality of semiconductor laser device elements, at least one of which has a means for preventing the injection of current in the vicinity of one facet or both facets.

Abstract: A semiconductor laser device comprises a p-type semiconductor substrate and a multi-layered crystal structure with an active layer for laser-oscillating operation, the multi-layered crystal structure being disposed on the substrate and having a striped channel area through which current is supplied to the active layer and a light-absorbing area positioned outside of the channeled area by which a difference between the amount of light to be absorbed inside of the channeled area and the amount of light to be absorbed outside of the channeled area is created, which causes a difference in the effective refractive index of the active layer, resulting in an optical waveguide in the active layer, wherein the light-absorbing area is constituted by an n-type semiconductor substance, but a portion of the n-type semiconductor substance positioned in the vicinity of at least one of both facets is replaced by a p-type semiconductor substance.

Abstract: A semiconductor laser device comprising a double-heterostructure that is composed of an active layer and a pair of cladding layers sandwiching the active layer therebetween, and a stripe structure that is disposed on the double-heterostructure, the stripe structure being composed of a current blocking layer with a conductive type different from that of the adjacent cladding layer, and the current blocking layer having a striped groove constituting a current path, wherein the cladding layer that contacts the current blocking layer is composed of an In.sub.1-s Ga.sub.s P.sub.1-t As.sub.t crystal material (wherein 0.51.ltoreq.s.ltoreq.1, 0.ltoreq.t.ltoreq.1 and s=2.04t-1.04).