Abstract: The semiconductor laser of this invention includes an active layer formed in a c-axis direction, wherein the active layer is made of a hexagonal-system compound semiconductor, and anisotropic strain is generated in a c plane of the active layer.

Abstract: An integrated semiconductor laser apparatus is constructed in such an arrangement that a core layer is located in the proximity of an active layer so as to be in an evanescent-field area of light propagating in the active layer and that a carrier concentration of a second cladding layer is higher than that of a first cladding layer. Thus, most evanescent waves of light propagating in the core layer propagate in the first cladding layer of the low carrier concentration. Since the rate of evanescent waves absorbed by carriers is very low, the integrated semiconductor laser apparatus can propagate the light with small losses.

Abstract: The present invention provides a resonant cavity including a planar two-dimensional periodic dielectric structure which exhibits a photonic band gap and a defect in the periodic dielectric structure which results in an electromagnetic mode within the photonic band gap. The photonic band gap effects an in-plane spacial confinement of electromagnetic radiation generated within the structure. The electromagnetic radiation is vertically confined by total internal reflection.

Abstract: An optical disk drive has an aberration detector and an aberration correction circuit. A semiconductor laser device made of semiconductor crystals constituting a semiconductor laser light source includes an active layer for performing light amplification through current injection and guiding light in waveguide, a reflection member for reflecting light into said active layer, and a top electrode and a bottom electrode used for current injection to the active layer, wherein the top electrode is divided into a main electrode and a plurality of subsidiary electrodes, and injection current to the subsidiary electrodes is controlled so as to correct an aberration generated at an optical focussing system and an optical disk.

Abstract: A point-to-point optical network for interconnecting processing elements uses a two-dimensional array of chips, each of which includes a two-dimensional array of lasers that are used to target a two-dimensional array of photodetectors. A two-dimensional array of lenslets together with a spherical lens are used to focus light from a laser in the j, k position in any one of the laser arrays in any one of the chips on the particular photodetector in the j,k position in the photodetector array.

Abstract: A semiconductor laser includes a first conductivity type semiconductor substrate, a first conductivity type lower cladding layer, a quantum well structure active layer including alternately laminated barrier and well layers, a disordered region extending to laser resonator facets, a second conductivity type first upper cladding layer disposed on the quantum well structure active layer, a ridge structure disposed on the first cladding layer, and having a first region not proximate the laser resonator facets including a second conductivity type second upper cladding layer and a second conductivity type first contact layer and a second region, proximate a laser resonator facet having a first conductivity type first semiconductor layer of the same material and thickness as the second upper cladding layer and a first conductivity type second semiconductor layer of same material as the first contact layer, a first conductivity type current blocking layer having a band gap energy larger than that of the second upper

Abstract: A ferrule for an optical fiber connector, through which an end of an optical fiber to be connected is inserted to fix the optical fiber thereto, is disclosed. In the ferrule, a boundary part between an optical fiber-inserting hole and an optical fiber-inserting opening is formed into a continuously curved surface. The surface defining the optical fiber-inserting hole is an unabraded surface formed of a material as calcined, whereby a slightly irregular grain boundary surface composed of particles 0 the material is formed at such a surface.

Abstract: A surface emitting laser device with at least two active regions in one and the same optical, vertical cavity wherein the active regions are electrically connected in series.

Abstract: An optical semiconductor device includes a semiconductor laser diode having a first electrode for receiving a current for driving the laser diode, and a grounding electrode; a modulator for modulating light emitted from the semiconductor laser diode, the modulator having a second electrode for receiving a current for driving the modulator, and a grounding electrode connected to the grounding electrode of the semiconductor laser diode; a first resistor having a terminal connected to the first electrode of the laser diode; a second resistor connected between the second electrode of the modulator and the grounding electrode of the modulator; and a third resistor having a first terminal connected to the grounding electrode of the modulator and a grounded second terminal.

Abstract: The present invention relates to a semiconductor laser control method used preferably for a reading control system such as a bar code reading device and to a semiconductor laser control device employing the above method. The object of the invention is to provide a semiconductor laser control device which can be controlled based on the output of a semiconductor laser, provides a stable laser output in a noise environment, enables easy output adjustment, and is immune to external thermal or electrical noises. In the semiconductor laser control method where the light amount of a light amount to current controllable semiconductor laser is subjected to a feedback control with a predetermined time constant while it is monitored, when the light amount is less than a predetermined value, the semiconductor laser is subjected to an feedback control with a first time constant. When the light amount is more than a predetermined value, the semiconductor laser is subjected to a feedback control with a second time constant.

Abstract: A high power monomode laser arrangement is able to manipulate the output from a high power laser diode array pump source using a computer-generated hologram to launch a high proportion of the pump source light into a multimode fibre portion including input reflector. A monomode fibre portion with the same fundamental-mode spot size as the multimode fibre portion is optically coupled to the multimode fibre portion and includes a reflector which reflects only the fundamental mode of the multimode and monomode fibre portions. The fundamental mode reflection forced by the monomode fibre portion provides the feedback necessary to force predominantly fundamental mode oscillation which enables stimulated emission in only the fundamental mode.

Abstract: A solid-state laser in which a rod (10) of lasing material is held within an optical cavity formed within a cooling block (40) having a highly surface facing the rod. A longitudinal slit (44) formed in the block from the optical cavity to the outside allows the pumping light from an emission line (36) of semiconductor stripe lasers (30) fabricated on a laser bar (28) to irradiate the laser rod and multiply reflect within the optical cavity. Thereby, pump light is efficiently absorbed by the laser rod, and the laser rod is thermally controlled. Alternatively, cooling liquid (124) can flow axially along the laser rod and within an axially extending optical cavity formed by a reflective coating (125) deposited on a tube (122) enclosing the cooling liquid and having a slit (126) through which pump light is irradiated.

Abstract: To overcome the dilemma on device design in control of waveguide mode experienced in the conventional weak wave-guide-laser and SCH structure laser, realize higher output and lower dispersion of radiation beam, and improve the waveguide mode, on both sides of an active layer, carrier blocking layers for reducing the waveguide function of the active layer are provided, and waveguide layers are provided on both outer sides of the carrier blocking layers, and cladding layers are provided on both outer sides of the waveguide layers, the active layer is lamination of side barrier layers and a quantum well layer sandwiched therebetween, or side barrier layers, and a quantum well layer and a barrier layer sandwiched therebetween, the composition of the quantum well layer is Ga.sub.y In.sub.1-y As (0.6<y<1.0), and the carrier blocking layers are made of a material having a wider band gap and a lower refractive index than the material of the waveguide layers.

Abstract: The LAMPS module is a compact, back cooled, vertically stacked, two-dimensional, incoherent array of diode laser bars featuring all-soldered construction with partial collimation of the emitting diode laser light to form a laser power source that can be transformed into a laser line source of exceptional brightness. The array includes a diode laser unit which comprises a diode laser bar, an electrode, and a substrate soldered to a heat sink. The diode laser unit is joined by soldering to an electrical isolator plate, and the isolator plate is joined to a heat exchanger by soldering for removal of waste heat. The invention includes a method for forming the array and a heat exchanger for removing heat from the array.

Abstract: A semiconductor laser comprises: a first cladding layer of a first conduction type; an active layer stacked on the first cladding layer; and a second cladding layer of a second conduction type stacked on the active layer. The first cladding layer, the active layer and the second cladding layer are made of II-VI compound semiconductors. Pulse oscillation occurs with characteristics of a threshold current I.sub.th (A), a threshold voltage V.sub.th (V) of the diode composed of the first cladding layer, the active layer and the second cladding layer, a differential resistance R.sub.S (.OMEGA.) of the diode after the rising, a thermal resistance R.sub.t (K/W) and a characteristic temperature T.sub.0 (K). When two amounts .alpha. and .beta. are defined by:.alpha..ident.(R.sub.t /T.sub.0)I.sub.th V.sub.th.beta..ident.(R.sub.t /T.sub.0)R.sub.S I.sub.th.sup.2the point (.alpha., .beta.) exists in an area on the .alpha.-.beta. plane surrounded by the straight line .alpha.=0, the straight line .beta.

Abstract: A semiconductor laser device includes a structure in which a first conductivity AlGaInP first cladding layer, an active layer, a second conductivity type AlGaInP second cladding layer, a second conductivity type AlGaInP intermediate layer, and a second conductivity type AlGaInP third cladding layer are successively epitaxially grown on a first conductivity type GaAs semiconductor substrate. The intermediate layer is within a profile of light produced in the active layer and includes AlGaInP layers having a band gap energy smaller than the band gap energy of the second cladding layer and the third cladding layer and larger than the band gap energy of the active layer. The intermediate layer has a multi-layer structure in which (Al.sub.x Ga.sub.1-x)InP layers (0.ltoreq.x.ltoreq.0.2) and (Al.sub.x Ga.sub.1-x)InP layers (0.5.ltoreq.x.ltoreq.1) are alternatingly laminated.

Abstract: A semiconductor laser includes an n type semiconductor substrate, an n type cladding layer, an active layer having an effective band gap energy, a p type cladding layer, and a tunnel diode structure including a high dopant concentration p type semiconductor layer and a high dopant concentration n type semiconductor layer having an effective band gap energy larger than the effective band gap energy of the active layer, a p side electrode disposed on the tunnel diode structure, and an n side electrode disposed on the rear surface of the n type semiconductor substrate. Since this semiconductor laser includes the tunnel diode structure disposed in the reverse bias direction with respect to the current flow direction, the contact resistivity of the ohmic contact of the p side electrode is lowered as compared to the case where the p side electrode is disposed on a p type semiconductor layer. The effective contact resistivity of the p side electrode is reduced.

Abstract: A semiconductor laser device comprising a first lead having a chip mounting part provided at the front end, at least one second lead separated from the first lead, a semiconductor laser element mounted on the chip mounting part, connecting means for electrically connecting the electrode of the semiconductor laser element and at least one second lead, and a frame body made of insulating material disposed so as to surround the semiconductor laser device and connecting means, and fixed to the first lead and second lead. In this semiconductor laser device, transparent resin is not used for sealing, and hence deterioration of light exit characteristic does not occur. Besides, because of the structure of fixing the leads to the frame body, it is rigid and excellent in reliability, and a multiplicity can be manufactured at once, so that it is easy to manufacture and is excellent in mass producibility.

Abstract: A vertical cavity surface emitting laser for emitting visible light, including a first mirror stack having a first portion of a first epitaxially grown material system and a second portion of a second epitaxially grown material system, an active region disposed on the first mirror stack, and a second mirror stack disposed on the active region.

Abstract: An optical probe for sensing presence of small moving particles passing through a defined sensing region comprises:i) an emitter optic fiber for transmitting from its tip radiant energy outwardly of the probe;ii) a receptor optic fiber for receiving radiant energy reflected by such particles moving through said sensing region;iii) a lens for focusing radiant energy emitted from the emitter tip into a focal region, spaced outwardly of the probe and which diverges outwardly into a defined high density radiant energy region;iv) the receptor optic fiber defining a diverging viewing region projecting outwardly towards the high density radiant energy region, the receptor optic fiber being positioned relative to the lens to project the viewing region to overlap a useful portion of the high density radiant energy region to define thereby the sensing region. This sensor is particularly useful in monitoring the flow characteristics of catalytic particles in a catalytic reactor for cracking of gasoline constituents.