Abstract: The present invention provides a QCL device with an electrically controlled refractive index through the Stark effect. By changing the electric field in the active area, the energy spacing between the lasing energy levels may be changed and, hence, the effective refractive index in the spectral region near the laser wavelength may be controlled.

Abstract: The present invention provides a QCL device with an electrically controlled refractive index through the Stark effect. By changing the electric field in the active area, the energy spacing between the lasing energy levels may be changed and, hence, the effective refractive index in the spectral region near the laser wavelength may be controlled.

Abstract: A semiconductor light source comprises a substrate, lower and upper claddings, a waveguide region with imbedded active area, and electrical contacts to provide voltage necessary for the wavelength tuning. The active region includes single or several heterojunction periods sandwiched between charge accumulation layers. Each of the active region periods comprises higher and lower affinity semiconductor layers with type-II band alignment. The charge carrier accumulation in the charge accumulation layers results in electric field build-up and leads to the formation of generally triangular electron and hole potential wells in the higher and lower affinity layers. Nonequillibrium carriers can be created in the active region by means of electrical injection or optical pumping. The ground state energy in the triangular wells and the radiation wavelength can be tuned by changing the voltage drop across the active region.

Abstract: Disclosed are a semiconductor device and method of manufacturing the same comprising a substrate, a mesa region adjacent to the substrate, an electroplated metal layer, for reducing the thermal resistance of the device, surrounding the mesa region, an insulator layer separating a side portion of the mesa region from the electroplated metal layer, a heat sink, a bonding layer adjacent to the heat sink, and a second metal layer in between the substrate and the heat sink, wherein the substrate is adjacent to the bonding layer, and wherein the electroplated metal layer dimensioned and configured to have a thickness of at least half a thickness of the mesa region; and to laterally spread heat away from the mesa region. The mesa region comprises a first cladding layer adjacent to the substrate, an active region adjacent the first cladding layer, and a second cladding layer adjacent to the active region.

Abstract: Disclosed are a semiconductor device and method of manufacturing the same comprising a substrate, a mesa region adjacent to the substrate, an electroplated metal layer, for reducing the thermal resistance of the device, surrounding the mesa region, an insulator layer separating a side portion of the mesa region from the electroplated metal layer, a heat sink, a bonding layer adjacent to the heat sink, and a second metal layer in between the substrate and the heat sink, wherein the substrate is adjacent to the bonding layer, and wherein the electroplated metal layer dimensioned and configured to have a thickness of at least half a thickness of the mesa region; and to laterally spread heat away from the mesa region. The mesa region comprises a first cladding layer adjacent to the substrate, an active region adjacent the first cladding layer, and a second cladding layer adjacent to the active region.

Abstract: Cladding layers for semiconductor lasers provide improved heat transfer and optical confinement properties. The cladding layers may comprise superlattices such as AlSb/GaAs, AlSb/AlAs, AlSb/GaSb/AlAs, AlGaSb/AlGaAs and AlSb/AlGaAs. The cladding layers may also comprise Al-As-Sb ternary alloys or Al-Ga-As-Sb quaternary alloys. Such cladding layers may be used in interband cascade lasers or other types of semiconductor lasers to significantly increase heat flow out of the active light-emitting region of the device, while providing improved optical confinement characteristics.

Abstract: Electrically conductive, embedded current injection layers are provided in combination with cladding layers to provided improved current conduction to the active light-emitting regions of semiconductor light-emitting devices. The embedded electrical contact layers are used to inject current directly into the active region of semiconductor light-emitting devices. Free-carrier loss within the cladding layers is reduced, and power efficiency is improved by eliminating voltage drops associated with current transport through the cladding layers. Moreover, use of the embedded current injection layers eliminates the need to transport current through the cladding layers thereby allowing the use of a wider range of materials for the cladding layers. The present current injection layers may be embedded in various semiconductor light-emitting devices, i.e.

Abstract: A quantum-confined Stark effect semiconductor optical modulator, operable to modulate light of a particular wavelength in the range of around 780 to 840 nm. A p-i-n diode having p, intrinsic and n regions, as well as first and second electrical contacts for application of a reverse bias voltage defines the modulator. The particular intrinsic region includes a plurality of semiconductor layers defining a plurality of quantum wells separated by barrier layers having a certain bandgap energy above that of the quantum wells. The quantum wells including at least two ultra-thin barrier layers within the quantum well and being of a material having a certain bandgap energy above that of the quantum wells. The width of each ultra-thin barrier layer is no more than approximately two molecular layers thick.

Abstract: An interband cascade (IC) light emitting device having narrow ridges, and a method of growing and fabricating the IC light emitting device is disclosed. The IC light emitting device produced by the method of the present invention has 18 active regions separated by n-type injection regions and a plurality of coupled quantum wells of Al(In)Sb, InAs, and Ga(In)Sb layers. The IC light emitting device produced according to the present method has a differential external quantum efficiency of at least 500%, a peak power output of at least 4W/facet, a power conversion efficiency of at least 14% in continuous wave at 80K, a power conversion efficiency of at least 18% in pulsed wave operation at 80K, a continuous wave operation temperature of 142 K or less, a thermal resistance of from about 24-29 K*cm2/kW and continuous wave output powers of at least 100 mW/facet at temperatures above 77K.

Abstract: An interband cascade (IC) light emitting device having narrow ridges, and a method of growing and fabricating the IC light emitting device is disclosed. The IC light emitting device produced by the method of the present invention has 18 active regions separated by n-type injection regions and a plurality of coupled quantum wells of Al(In)Sb, InAs, and Ga(In)Sb layers. The IC light emitting device produced according to the present method has a differential external quantum efficiency of at least 500%, a peak power output of at least 4W/facet, a power conversion efficiency of at least 14% in continuous wave at 80K, a power conversion efficiency of at least 18% in pulsed wave operation at 80K, a continuous wave operation temperature of 142 K or less, a thermal resistance of from about 24-29 K*cm2/kW and continuous wave output powers of at least 100 mW/facet at temperatures above 77K.

Abstract: A valve-less fluid control circuit for controlling rhythmic action devices, such as circulatory assist devices. The fluid control circuit has a plurality of pressure sensitive fluid oscillators for circulating a fluid. Each fluid oscillator includes a capacitance chamber unit for peristaltic pumping of fluid after being filled via an input conduit and a resistance conduit. A first control conduit provides an outlet of fluid from the capacitance unit during peristaltic pumping, and when the pressure of the fluid in the first control conduit reaches a certain level relative to the pressure of fluid in the input conduit, the fluid is directed through an interactive region and exits the first fluid oscillator through an exhaust conduit.

Abstract: A method for improving images of surface features of a sample, constructed by a scanning probe microscope, includes constructing images of surface features of a sample with a scanning probe microscope; measuring a displacement of the sample that occurs during the constructing step; and correcting the images using the measured displacement. An apparatus for improving images of surface features of a sample, constructed by a scanning probe microscope, includes a vacuum chamber; a sample holder disposed in the vacuum chamber; at least one spring connected between the vacuum chamber and the sample holder; at least one magnet disposed in the vacuum chamber for damping vibrations of the sample holder; a probe and piezo tube assembly disposed in the vacuum chamber for scanning surface features of a sample; and an interferometer disposed in the vacuum chamber wherein the interferometer measures a distance between the sample and a point fixed with respect to the sample.

Abstract: An electromagnetic launcher includes a single or multi-polar, multi-phase electrical generator powered by an external source; electrical conductors leading from output coils of the generator and from a center point joining the output coils; a plurality of rails connected to the electrical conductors; and an armature having at least two channels; whereby there is at least one position of the armature along the plurality of rails where current flows simultaneously through both of the at least two channels.

Abstract: An apparatus for determining thickness of a wall or coal seam includes a ice for measuring the time of sound travel through the thickness; a flexible isolation bellows that mechanically supports the device for measuring the time of sound travel; and a retractable isolation arm attached to the isolation bellows. The device for measuring the time of sound travel may be a single-beam pulse sonar system. The single-beam pulse sonar system includes a pulse generator, a power amplifier, a transmit/receive switch, a reciprocal acoustic transducer, a receiver for determining the thickness, and a display and/or an electronic feedback circuit for steering an autonomous miner.

Abstract: Nickel and cobalt contained in aqueous sulfate solution are separately recovered by counter-current solvent extraction using a cobalt-selective organic extractant while scaling of equipment and cobalt recycle are minimized by controlling aqueous pH at the extraction, scrubbing and stripping stages to maximize cobalt loading and selectivity of the extractant while loading scale-causing ions such as calcium and magnesium in the extractant and removing them from the circuit with the aqueous cobalt strip solution.

Abstract: A hydrometallurgical process is provided for the recovery of molybdenum values from a molybdenum disulfide concentrate containing copper. The process comprises forming an aqueous slurry of finely divided molybdenum concentrate of carbonates and hydroxides of alkali metals, and pressure leaching the slurry in the presence of oxygen at an elevated temperature and pressure for a time sufficient to effect conversion of the contained molybdenum values to alkali metal molybdate and provide a residue containing copper oxide or basic copper carbonate from which copper is later recovered. The molybdenum values are recovered from solution by solvent extraction and the solvent thereafter stripped of the molybdenum as ammonium molybdenum using ammonium hydroxide. The molybdenum is recovered as crystals of ammonium molybdate by crystallization, e.g., by evaporating the stripping solution.

Abstract: An optoelectronic device comprises a detector, an emitter and a modulator corporated into a single semiconductor chip. The optoelectronic device provides electrical isolation and optical interconnection (via waveguides) of the components of the semiconductor chip. Contacts for providing forward and reverse bias voltages are included in the device. The optoelectronic device is fabricated by growing a strained-layer quantum diode structure to produce a piezoelectric field in a quantum well, electrically isolating portions of the structure, and optically interconnecting portions of the structure. The fabrication is carried out by using an implant process or an etching process, and without having to use either regrowth techniques or packaging together of multiple optical elements.