Abstract: A semiconductor laser device includes: a first cladding layer, which is made of a nitride semiconductor of a first conductivity type and is formed over a substrate; an active layer, which is made of another nitride semiconductor and is formed over the first cladding layer; and a second cladding layer, which is made of still another nitride semiconductor of a second conductivity type and is formed over the active layer. A spontaneous-emission-absorbing layer, which is made of yet another nitride semiconductor of the first conductivity type and has such an energy gap as absorbing spontaneous emission that has been radiated from the active layer, is formed between the substrate and the first cladding layer.

Abstract: A semiconductor laser device includes a first semiconductor laser element for emitting a first laser light having a first oscillation wavelength of ?1 and a second semiconductor laser element for emitting a second laser light having a second oscillation wavelength of ?2 (wherein ?2??1), which are formed on a single substrate. A first dielectric film which has a refractive index of n1 with respect to a wavelength ? between the first oscillation wavelength ?1 and the second oscillation wavelength ?2 and has a film thickness of approximately ?/(8n1) is formed at light emitting facets in the first semiconductor laser element and the second semiconductor laser element, from which the laser lights are emitted, and a second dielectric film having a refractive index of n2 and a film thickness of ?/(8n2) are formed on the first dielectric film.

Abstract: A semiconductor laser device includes: a first cladding layer, which is made of a nitride semiconductor of a first conductivity type and is formed over a substrate; an active layer, which is made of another nitride semiconductor and is formed over the first cladding layer; and a second cladding layer, which is made of still another nitride semiconductor of a second conductivity type and is formed over the active layer. A spontaneous-emission-absorbing layer, which is made of yet another nitride semiconductor of the first conductivity type and has such an energy gap as absorbing spontaneous emission that has been radiated from the active layer, is formed between the substrate and the first cladding layer.

Abstract: To provide a semiconductor laser device for which a horizontal divergence angle of a laser beam can be improved independently of optimization of other properties such as a cladding layer thickness and a current injected region size. A current blocking layer covers a larger area of a p-type second cladding layer and p-type cap layer extending in a resonator length direction, on a light emitting end face side than on an opposite end face side. Thus, current uninjected regions are formed in an optical waveguide. The current blocking layer (current uninjected region) on the light emitting end face side is set long enough to prevent carriers, which flow in from a current injected region, from reaching alight emitting end face. In this way, a light intensity distribution of a near-field pattern on the light emitting end face is concentrated, thereby increasing a horizontal divergence angle of a laser beam.

Abstract: In a semiconductor laser 1, a current blocking layer 19 covers a p-type 2nd cladding layer 17 and a p-type cap layer 18 that extend in a lengthwise direction of an optical resonator, at both a light-emission end and an end opposite the light-emission end, to thus form non-current injection regions in an optical waveguide. By making current blocking layer 19 at the light-emission end large enough that carriers flowing from a current injection region do not reach the light-emission end surface, the light intensity distribution in the near field at the light-emission end surface is strongly concentrated, allowing the horizontal divergence angle of an emerging laser beam to be enlarged. This structure makes it possible to enlarge the horizontal divergence angle independently after having optimized the thickness of cladding layers and the size of the current injection region.

Abstract: A semiconductor laser includes an n-type semiconductor substrate, an n-type clad layer, an active layer, a p-type first clad layer, a current blocking layer, a p-type second clad layer and a p-type contact layer stacked in this order form the bottom. A p-side ohmic electrode is formed on the p-type contact layer and an n-side ohmic electrode is formed on a back surface of the n-type semiconductor substrate. A stripe is formed in the current blocking layer so as to extend in the optical oscillator direction. In a center portion of the p-type contact layer, a slit is formed so as to extend in the optical oscillator direction and intersect with the stripe with right angles.

Abstract: The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AluGavInwN, wherein 0?u, v, w?1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlxGayInzN, wherein 0?x, y, z?1 and x+y+z=1, by using, as a seed crystal, C planes corresponding to top faces of the convexes exposed from the mask film.

Abstract: A semiconductor laser device (10) includes a resonant cavity (12) in which a quantum well active layer (11) made up of barrier layers of gallium nitride and well layers of indium gallium nitride is vertically sandwiched between at least light guide layers of n- and p-type aluminum gallium nitride. An end facet reflective film (13) is formed on a reflective end facet (10b) opposite to a light-emitting end facet (10a) in the resonant cavity (12). The end facet reflective film (13) has a structure including a plurality of unit reflective films (130), each of which is made up of a low-refractive-index film (13a) of silicon dioxide and a high-refractive-index film (13b) of niobium oxide. The low-and high-refractive-index films are deposited in this order on the end facet of the resonant cavity (12).

Abstract: A semiconductor laser device includes: a first cladding layer, which is made of a nitride semiconductor of a first conductivity type and is formed over a substrate; an active layer, which is made of another nitride semiconductor and is formed over the first cladding layer; and a second cladding layer, which is made of still another nitride semiconductor of a second conductivity type and is formed over the active layer. A spontaneous-emission-absorbing layer, which is made of yet another nitride semiconductor of the first conductivity type and has such an energy gap as absorbing spontaneous emission that has been radiated from the active layer, is formed between the substrate and the first cladding layer.

Abstract: A semiconductor laser device (10) includes a resonant cavity (12) in which a quantum well active layer (11) made up of barrier layers of gallium nitride and well layers of indium gallium nitride is vertically sandwiched between at least light guide layers of n- and p-type aluminum gallium nitride. An end facet reflective film (13) is formed on a reflective end facet (10b) opposite to a light-emitting end facet (10a) in the resonant cavity (12). The end facet reflective film (13) has a structure including a plurality of unit reflective films (130), each of which is made up of a low-refractive-index film (13a) of silicon dioxide and a high-refractive-index film (13b) of niobium oxide. The low-and high-refractive-index films are deposited in this order on the end facet of the resonant cavity (12).

Abstract: The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AluGavInwN, wherein 0≦u, v, w ≦1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlxGayInzN, wherein 0≦x, y, z≦1 and x+y+z=1, by using, as a seed crystal, Cplanes corresponding to top faces of the convexes exposed from the mask film.

Abstract: A load sensor is formed of first and second opposing electrode members. The members make contact to mutually conduct electrically when a load is applied to the load sensor. The first electrode member consists of an elastic tube having at least a part of the circumferential segment formed into a conductive portion. The second electrode member consists of a flexible center electrode with conductivity on at least the outer circumferential portion positioned inside the elastic tube of the first electrode member so that the conducting surfaces face each other. An insulating linear member is wound around the center electrode at a predetermined winding distance.

Abstract: A load sensor 10 is provided with an elastic conductive tube 21, and a first electrode member 22 and second electrode member 23 separated by a distance in the longitudinal direction. The load sensor 10 is further provided with an elongated insertion member 24 to be inserted into the elastic conductive tube 21, and envelope members 25, which are provided at predetermined intervals in the longitudinal direction to enclose the insertion member 24, and together with the insertion member 24 are inserted into the tube 21 to separate the insertion member 24 from the tube 21. When the tube 21 is bent by the application of a load, the electrode members 22 and 23 contact the tube 21. The load is detected by determining whether the electrode members 22 and 23 have been rendered conductive via the tube 21. The sensitivity of the sensor 10 can be easily controlled by adjusting the interval between envelope members 25 and the thicknesses thereof.

Abstract: The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AluGavInwN, wherein 0≦u, v, w≦1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlxGayInzN, wherein 0≦x, y, z≦1 and x+y+z=1, by using, as a seed crystal, C planes corresponding to top faces of the convexes exposed from the mask film.

Abstract: First, the substrate temperature is set to 1020° C., and an n-type cladding layer (14) made of n-type Al0.1Ga0.9N, an n-type optical guide layer (15) made of n-type GaN, and a flatness maintenance layer (16) made of n-type Al0.2Ga0.8N for maintaining the surface flatness of the n-type optical guide layer (15) by suppressing re-evaporation of the constituent atoms of the n-type optical guide layer (15), are grown in this order on a substrate (11) made of sapphire. Then, the supply of a group III material gas is stopped, the substrate temperature is decreased to 780° C., and the carrier gas is switched from a hydrogen gas to a nitrogen gas. Then, an active layer (17) having a multiple quantum well structure is grown by introducing NH3 as a group V source and selectively introducing TMI and TMG as a group III source.

Abstract: A nitride semiconductor laser device includes an n-type contact layer of n-type GaN and an n-type cladding layer of n-type Al0.35Ga0.65N formed on a substrate of sapphire. On the n-type cladding layer, a multiple quantum well active layer of Al0.2Ga0.8N/Al0.25Ga0.75N, a p-type leak barrier layer of p-type Al0.5Ga0.5N0.975P0.025 and a p-type cladding layer of p-type Al0.4Ga0.6N0.98P0.02 are successively formed. The p-type leak barrier layer has a wider energy gap than the n-type cladding layer, and the p-type leak barrier layer and the p-type cladding layer include phosphorus for making an acceptor level shallow with keeping a wide energy gap.

Abstract: In the foreign object insertion detector device, the light (infrared rays) is transmitted into the internal space 13 of a tube body 11 implanted into a weather strip 9 and formed of elastic material and, if there occurs the insertion of a foreign object, then the foreign object produces a pressing force and applies the pressing force to the tube body 11 to thereby deform the tube body 11. If the tube body 11 is deformed in this manner, then the quantity of the light transmitted through the internal space 13 is caused to decrease. By judging whether a decrease in the quantity of the light transmitted through the internal space 13 is present or absent, the insertion of the foreign object can be detected.

Abstract: This load sensor 10 comprises an elastic conductive tube 11, a center electrode member 13 in which at least the outer circumferential portion has conductivity, the center electrode member being provided within the elastic conductive tube 11, and an insulating linear member 15 in which at least the outer circumferential portion is an elongated shape having insulation properties, the insulating linear member being wound spirally on the center electrode member 13 at a predetermined winding distance. The insulating linear member 15 is constructed of an enamel wire in which a metal wire is coated with enamel or a coat electric wire in which a metal wire is coated with resin. The center electrode member 13 is formed by transversely winding a conductive metal wire 23 spirally on the outer circumference of a center member 21 constructed by coating elastic insulating material on a center reinforcing member made of aramid fibers.

Abstract: Laser light emitted from the wavelength-locked GaN semiconductor laser is collimated through a collimation lens, led through a polarization beam splitter and a ¼ wavelength plate, and converged by a focus lens so as to be radiated on pits formed in an optical disk medium. The signal light from the optical disk medium is collimated by the focus lens, and has its polarization direction turned by the ¼ wavelength plate by 90° relative to its polarization direction before being returned from the optical disk medium. As a result, the signal light is reflected from the polarization beam splitter so as to be converged on the optical detector by the focus lens.

Abstract: A load sensor 10 is provided with an elastic conductive tube 21, and a first electrode member 22 and second electrode member 23 separated by a distance in the longitudinal direction. The load sensor 10is further provided with an elongated insertion member 24 to be inserted into the elastic conductive tube 21, and envelope members 25, which are provided at predetermined intervals in the longitudinal direction to enclose the insertion member 24, and together with the insertion member 24 are inserted into the tube 21 to separate the insertion member 24 from the tube 21. When the tube 21 is bent by the application of a load, the electrode members 22 and 23 contact the tube 21. The load is detected by determining whether the electrode members 22 and 23 have been rendered conductive via the tube 21. The sensitivity of the sensor 10 can be easily controlled by adjusting the interval between envelope members 25 and the thicknesses thereof.