Abstract: A semiconductor laser element that includes a stripe-shaped light-emitting region and that is formed by adhering a surface of the semiconductor laser element on a side opposite to a semiconductor substrate and a submount to each other by a solder layer includes a terrace section on a surface of the semiconductor laser element that is adhered by the solder layer, the terrace section being separated from a ridge portion, which is a current-carrying portion, by a grooved portion. A top surface of a region including the grooved portion is covered by a metal. The terrace section is divided into a plurality of portions that are disposed in a scattered manner.

Abstract: A semiconductor laser element that includes a stripe-shaped light-emitting region and that is formed by adhering a surface of the semiconductor laser element on a side opposite to a semiconductor substrate and a submount to each other by a solder layer includes a terrace section on a surface of the semiconductor laser element that is adhered by the solder layer, the terrace section being separated from a ridge portion, which is a current-carrying portion, by a grooved portion. A top surface of a region including the grooved portion is covered by a metal. The terrace section is divided into a plurality of portions that are disposed in a scattered manner.

Abstract: In a self-pulsation type semiconductor laser, a first clad layer of a first conductivity type, an active layer, and a second clad layer of a second conductivity type having a striped ridge portion are successively stacked on a semiconductor substrate of the first conductivity type. In an embedding layer formed on either side surface of the ridge portion and on either flat portion other than the ridge portion of the second clad layer, a saturable absorption layer is provided on a material layer having a refractive index equal to or greater than that of the second clad layer and not absorbing laser light.

Abstract: In a self-pulsation type semiconductor laser, a first clad layer of a first conductivity type, an active layer, and a second clad layer of a second conductivity type having a striped ridge portion are successively stacked on a semiconductor substrate of the first conductivity type. In an embedding layer formed on either side surface of the ridge portion and on either flat portion other than the ridge portion of the second clad layer, a saturable absorption layer is provided on a material layer having a refractive index equal to or greater than that of the second clad layer and not absorbing laser light.

Abstract: In a semiconductor laser element, an active layer is sandwiched between first-conductivity type and second-conductivity type cladding layers, and a second-conductivity type contact layer is disposed above the second cladding layer with an intermediate bandgap layer interposed between the second cladding layer and the contact layer, the second-conductivity type contact layer having a bandgap different from a bandgap of the second-conductivity type cladding layer, the intermediate bandgap layer having an intermediate bandgap between the bandgaps of the second-conductivity type cladding layer and the second-conductivity type contact layer. The second-conductivity type contact layer has at least a first contact layer, an intermediate second contact layer and a third contact layer stacked in this order and the second contact layer has an impurity density lower than impurity densities of the first and third contact layers.

Abstract: There is disclosed a semiconductor laser device characterized in that an electric current path from a p-type cap layer to a p-type cladding layer has a ridge stripe consisting of at least three semiconductor layers, wherein each layer has a different band gap, a top width of the p-type cladding layer is 2.5 &mgr;m or smaller, and a differential resistance of the device at a working current is 8 &OHgr; or smaller. According to the present invention, a self-excited oscillation type semiconductor laser device and a real-guide type high power semiconductor laser device which have a low resistance and the high reliability at a high temperature can be provided.

Abstract: In a semiconductor laser element, an active layer is sandwiched between first-conductivity type and second-conductivity type cladding layers, and a second-conductivity type contact layer is disposed above the second cladding layer with an intermediate bandgap layer interposed between the second cladding layer and the contact layer, the second-conductivity type contact layer having a bandgap different from a bandgap of the second-conductivity type cladding layer, the intermediate bandgap layer having an intermediate bandgap between the bandgaps of the second-conductivity type cladding layer and the second-conductivity type contact layer. The second-conductivity type contact layer has at least a first contact layer, an intermediate second contact layer and a third contact layer stacked in this order and the second contact layer has an impurity density lower than impurity densities of the first and third contact layers.

Abstract: A self-pulsation type semiconductor laser device includes a semiconductor substrate of a first conductive type and a multilayered structure including at least an active layer provided on the semi conductor substrate. The multilayered structure includes a first cladding layer of the first conductive type provided below the active layer, a second cladding layer of a second conductive type having a striped ridge portion provided above the active layer and a saturable absorbing film provided over the second cladding layer. The saturable absorbing film includes an accumulation region for accumulating photoexcited carriers. The accumulating region is provided apart from a surface of the second cladding layer.

Abstract: A semiconductor laser device includes a substrate; a double hetero structure having an n-type cladding layer, an active layer, and a p-type cladding layer, which is formed on an upper face of the substrate; and electrodes formed on a lower face of the substrate and on an upper face of the double hetero structure, wherein the double hetero structure further includes a p-type hetero-barrier layer formed between the p-type cladding layer and the active layer, which is strained by compression due to a lattice mismatch.

Abstract: A method for fabricating an AlGaInP semiconductor light emitting device having a substrate and a multilayer structure including an AlGaInP first semiconductor layer formed on the substrate. The method comprises the steps of removing part of the multilayer structure so that the first semiconductor layer is exposed, irradiating with plasma beams an oxide film formed on the exposed first semiconductor layer with the substrate temperature being kept at 500.degree. C. or less, so as to remove the oxide film from the first semiconductor layer and growing a second semiconductor layer on the first semiconductor layer.

Abstract: The disclosed light emitting semiconductor device has an n-type (or p-type) base region sandwiched by a p-type (or n-type) emitter region and a p-type (or n-type) collector region. An injecting voltage source is connected across the emittter region and base region so as to apply a constant voltage therebetween, while a control voltage source is connected across the emitter region and the collector region so as to selectively apply a reverse bias to a base-collector junction for controlling recombination of carriers injected to the base region. The control voltage source produces such non-emitting period voltage and emitting period voltage that carriers injected during the non-emitting period voltage are captured in the base region while the carriers thus captured are allowed to recombine during the emitting period voltage.