Abstract: In a nitride semiconductor laser device so structured as to suppress development of a step on nitride semiconductor layers, the substrate has the (11-20) plane as the principal plane, the resonator end surface is perpendicular to the principal plane, and, in the cleavage surface forming the resonator end surface, at least by one side of a stripe-shaped waveguide, an etched-in portion is formed as an etched-in region open toward the surface of the nitride semiconductor layers.

Abstract: A nitride semiconductor laser device has a nitride semiconductor substrate that includes a dislocation-concentrated region 102 and a wide low-dislocation region and that has the top surface thereof slanted at an angle in the range of 0.3° to 0.7° relative to the C plane and a nitride semiconductor layer laid on top thereof. The nitride semiconductor layer has a depression immediately above the dislocation-concentrated region, and has, in a region thereof other than the depression, a high-quality quantum well active layer with good flatness and without cracks, a layer that, as is grown, readily exhibits p-type conductivity, and a stripe-shaped laser light waveguide region. The laser light waveguide region is formed above the low-dislocation region. This helps realize a nitride semiconductor laser device that offers a longer life.

Abstract: In a nitride semiconductor laser chip so structured as to suppress development of a step on nitride semiconductor layers, the substrate has the (1-100) plane as the principal plane, the resonator facet is perpendicular to the principal plane, and, in the cleavage surface forming the resonator facet, at least by one side of a stripe-shaped waveguide, an etched-in portion is formed as an etched-in region open toward the surface of the nitride semiconductor layers.

Abstract: In a method for producing a nitride semiconductor light-emitting device according to the present invention, first, a nitride semiconductor substrate having groove portions formed is prepared. An underlying layer comprising nitride semiconductor is formed on the nitride semiconductor substrate including the side walls of the groove portions, in such a manner that the underlying layer has a crystal surface in each of the groove portions and the crystal surface is tilted at an angle of from 53.5° to 63.4° with respect to the surface of the substrate. Over the underlying layer, a light-emitting-device structure composed of a lower cladding layer containing Al, an active layer, and an upper cladding layer containing Al is formed. According to the present invention, thickness nonuniformity and lack of surface flatness, which occur when accumulating a layer with light-emitting-device structure of nitride semiconductor over the nitride semiconductor substrate, are alleviated while inhibiting occurrence of cracking.

Abstract: A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate that is transparent and has a refractive index ns for laser light, a first clad layer of a refractive index nc1, a second clad layer of a refractive index nc2, a third clad layer of a refractive index nc3, a first conductivity type guide layer of a refractive index ng, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in that order, wherein the waveguide has an effective refractive index ne, and the relationship nc2<(nc1, nc3)<ne<(ns, ng) is satisfied.

Abstract: In a method for producing a nitride semiconductor light-emitting device according to the present invention, first, a nitride semiconductor substrate having groove portions formed is prepared. An underlying layer comprising nitride semiconductor is formed on the nitride semiconductor substrate including the side walls of the groove portions, in such a manner that the underlying layer has a crystal surface in each of the groove portions and the crystal surface is tilted at an angle of from 53.5° to 63.4° with respect to the surface of the substrate. Over the underlying layer, a light-emitting-device structure composed of a lower cladding layer containing Al, an active layer, and an upper cladding layer containing Al is formed. According to the present invention, thickness nonuniformity and lack of surface flatness, which occur when accumulating a layer with light-emitting-device structure of nitride semiconductor over the nitride semiconductor substrate, are alleviated while inhibiting occurrence of cracking.

Abstract: A drive current is generated by mixing a pulse signal from a pulse generator and a DC current from a DC current power supply using a T circuit and injected into a nitride semiconductor laser having a horizontal light-confinement ridge structure. The horizontal light-confinement coefficient of the nitride semiconductor laser is between 85% and 99%. The time when the current waveform of the drive current is continuously over the threshold current of the nitride semiconductor laser ranges from 5 nsec to 1,000 nsec.

Abstract: A nitride semiconductor laser element includes a lower clad layer, a lower adjacent layer, a quantum well active layer, an upper adjacent layer and an upper clad layer in this order. The quantum well active layer includes a plurality of well layers formed of undoped InGaN, and an undoped barrier layer sandwiched between the well layers. The barrier layer includes a first layer formed of InGaN, a second layer formed of GaN, and a third layer formed of InGaN. The In composition ratio of the first layer and the In composition ratio of the third layer are less than half the In composition ratio of the well layer.

Abstract: A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate that is transparent and has a refractive index ns for laser light, a first clad layer of a refractive index nc1, a second clad layer of a refractive index nc2, a third clad layer of a refractive index nc3, a first conductivity type guide layer of a refractive index ng, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in that order, wherein the waveguide has an effective refractive index ne, and the relationship nc2<(nc1, nc3)<ne<(ns, ng) is satisfied.

Abstract: A light emitting apparatus comprises a light emitting section for emitting light, a color of the light being changed with a value of a driving current, and a driving section for driving the light emitting section so that the light emitting section emits light having a desired color and a desired intensity, by generating the driving current based on a signal designating the desired color and a signal designating the desired intensity and by applying the driving current to the light emitting section.

Abstract: A nitride semiconductor light emitting device includes at least a substrate, an active layer formed of a nitride semiconductor containing mainly In and Ga, a p-electrode and an n-electrode. At least one of the p-electrode and n-electrode is electrically separated into at least two regions.

Abstract: A light emitting apparatus comprises a light emitting section for emitting light, a color of the light being changed with a value of a driving current, and a driving section for driving the light emitting section so that the light emitting section emits light having a desired color and a desired intensity, by generating the driving current based on a signal designating the desired color and a signal designating the desired intensity and by applying the driving current to the light emitting section.

Abstract: A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate transparent and having a refractive index ns for laser light, a first clad layer of a refractive index nc1, a second clad layer of a refractive index nc2, a third clad layer of a refractive index nc3, a first conductivity type guide layer of a refractive index ng, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in this order, wherein the waveguide has an effective refractive index ne, and a relationship of nc2<(nc1, nc3)<ne<(ns, ng) is satisfied.

Abstract: In a nitride semiconductor light-emitting device, a cap is pressure-bonded on the top surface of a stem under electric discharge to form a package. The package encloses a heatsink, a nitride semiconductor laser element, electrode pins, and wires, and has sealed inside it a gas containing oxygen as a sealed atmosphere. At least the inner surface of the cap is plated with Ni and Pd, which are metals that can occlude hydrogen.

Abstract: According to an aspect of the present invention, a nitride semiconductor laser device includes a nitride semiconductor active layer, and a stripe-shaped waveguide for guiding light generated in the active layer. At least one pair of light-absorbing films are provided in at least local regions on the opposite sides of the stripe-shaped waveguide, to reach a distance within 0.3 ?m from the waveguide. According to another aspect of the present invention, a gan-based semiconductor laser device includes first conductivity type semiconductor layers, a semiconductor active layer and second conductivity type semiconductor layers stacked sequentially. The laser device further includes a ridge stripe provided to cause a refractive index difference for confinement of light in a lateral direction crossing a longitudinal direction of a cavity, and a current-introducing window portion provided on the ridge stripe.

Abstract: A semiconductor laser element has the following structure. In the clad layer, a difference in a light radiation loss between the basic horizontal-lateral mode and the 1st-order horizontal-lateral mode is 10 cm?1 or more. The refractive index of the clad layer is below an effective index against light in the basic horizontal-lateral mode, and the refractive index of the clad layer is equal to or more than an effective index against light in the 1st-order horizontal-lateral mode. The upper clad layer is provided only above a portion of the active layer, and thus is at least included in the ridge-stripe structure. This structure inhibits the I-L characteristic from suffering kink and realizes oscillations in the basic horizontal-lateral mode until output power reaches as high as 60–100 mW, in a peak output power of the semiconductor laser element at the time of a pulse current operation.

Abstract: A nitride semiconductor laser device has a nitride semiconductor substrate that includes a dislocation-concentrated region 102 and a wide low-dislocation region and that has the top surface thereof slanted at an angle in the range of 0.3° to 0.7° relative to the C plane and a nitride semiconductor layer laid on top thereof. The nitride semiconductor layer has a depression immediately above the dislocation-concentrated region, and has, in a region thereof other than the depression, a high-quality quantum well active layer with good flatness and without cracks, a layer that, as is grown, readily exhibits p-type conductivity, and a stripe-shaped laser light waveguide region. The laser light waveguide region is formed above the low-dislocation region. This helps realize a nitride semiconductor laser device that offers a longer life.

Abstract: In a method for producing a nitride semiconductor light-emitting device according to the present invention, first, a nitride semiconductor substrate having groove portions formed is prepared. An underlying layer comprising nitride semiconductor is formed on the nitride semiconductor substrate including the side walls of the groove portions, in such a manner that the underlying layer has a crystal surface in each of the groove portions and the crystal surface is tilted at an angle of from 53.5° to 63.4° with respect to the surface of the substrate. Over the underlying layer, a light-emitting-device structure composed of a lower cladding layer containing Al, an active layer, and an upper cladding layer containing Al is formed. According to the present invention, thickness nonuniformity and lack of surface flatness, which occur when accumulating a layer with light-emitting-device structure of nitride semiconductor over the nitride semiconductor substrate, are alleviated while inhibiting occurrence of cracking.

Abstract: In a wafer having an LD structure 251 formed on a GaN-based substrate 250, cleavage guide grooves 252 are formed in its surface by scribing from above the LD structure 251 with a diamond needle. The cleavage guide grooves 252 are formed one along each of stripe-shaped waveguides 253 formed parallel to the <1-100> direction of the wafer, and are formed in the shape of broken lines in the <11-20> direction of the wafer.

Abstract: A nitride semiconductor laser device using a group III nitride semiconductor also as a substrate offers excellent operation characteristics and a long laser oscillation life. In a layered structure of a group III nitride semiconductor formed on a GaN substrate, a laser optical waveguide region is formed elsewhere than right above a dislocation-concentrated region extending so as to vertically penetrate the substrate, and electrodes are formed on the top surface of the layered structure and on the bottom surface of the substrate elsewhere than right above or below the dislocation-concentrated region. In a portion of the top surface of the layered structure and in a portion of the bottom surface of the substrate right above and below the dislocation-concentrated region, dielectric layers may be formed to prevent the electrodes from making contact with those regions.