Abstract: A gain medium and an interband cascade laser, having the gain medium are presented. The gain medium can have one or both of the following features: (1) the thicknesses of the one or more hole quantum wells in the hole injector region are reduced commensurate with the thickness of the active hole quantum well in the active quantum well region, so as to place the valence band maximum in the hole injector region at least about 100 meV lower than the valence band maximum in the active hole quantum well; and (2) the thickness of the last well of the electron injector region is between 85 and 110% of the thickness of the first active electron quantum well in the active gain region of the next stage of the medium. A laser incorporating a gain medium in accordance with the present invention can emit in the mid-IR range from about 2.5 to 8 ?m at high temperatures with room-temperature continuous wave operation to wavelengths of at least 4.

Abstract: Methods for improving the performance of type-II and type-I ICLs, particularly in the mid-IR wavelength range, are provided. The electron injector of a type-II or a type-I ICL can be heavily n-doped to increase the ratio of electrons to holes in the active quantum wells, thereby increasing the probability of radiative recombination in the active quantum wells and reducing the threshold current density Jth needed to achieve lasing. For both type-II and type-I ICLs, the doping should have a sheet density in the low-1012 range. In either the type-II or the type-I case, in some embodiments, heavy doping can be concentrated in the middle quantum wells of the electron injector, while in other embodiments, doping with silicon can be shifted towards the active quantum wells.

Abstract: A gain medium and an interband cascade laser, having the gain medium are presented. The gain medium can have one or both of the following features: (1) the thicknesses of the one or more hole quantum wells in the hole injector region are reduced commensurate with the thickness of the active hole quantum well in the active quantum well region, so as to place the valence band maximum in the hole injector region at least about 100 meV lower than the valence band maximum in the active hole quantum well; and (2) the thickness of the last well of the electron injector region is between 85 and 110% of the thickness of the first active electron quantum well in the active gain region of the next stage of the medium. A laser incorporating a gain medium in accordance with the present invention can emit in the mid-IR range from about 2.5 to 8 ?m at high temperatures with room-temperature continuous wave operation to wavelengths of at least 4.

Abstract: An interband cascade gain medium is provided. The gain medium can include at least one thick separate confinement layer comprising Ga(InAlAs)Sb between the active gain region and the cladding and can further include an electron injector region having a reduced thickness, a hole injector region comprising two hole quantum wells having a total thickness greater than about 100 ?, an active gain quantum well region separated from the adjacent hole injector region by an electron barrier having a thickness sufficient to lower a square of a wavefunction overlap between a zone-center active electron quantum well and injector hole states, and a thick AlSb barrier separating the electron and hole injectors of at least one stage of the active region.

Abstract: A gain medium and an interband cascade laser, having the gain medium are presented. The gain medium can have one or both of the following features: (1) the thicknesses of the one or more hole quantum wells in the hole injector region are reduced commensurate with the thickness of the active hole quantum well in the active quantum well region, so as to place the valence band maximum in the hole injector region at least about 100 meV lower than the valence band maximum in the active hole quantum well; and (2) the thickness of the last well of the electron injector region is between 85 and 110% of the thickness of the first active electron quantum well in the active gain region of the next stage of the medium. A laser incorporating a gain medium in accordance with the present invention can emit in the mid-IR range from about 2.5 to 8 ?m at high temperatures with room-temperature continuous wave operation to wavelengths of at least 4.

Abstract: A gain medium and an interband cascade laser, an interband cascade amplifier, and an external cavity laser having the gain medium are presented.

Abstract: A surface plasmon polariton device that may be integrated onto a single microchip is disclosed. The device employs a laser that emits polarized light across a gap into a plasmonic waveguide. Surface plasmon polaritons are thereby created in an efficient matter. The device provides a source of surface plasmon polaritons at near infrared wavelengths in an integrated package.

Abstract: A gain medium and an interband cascade laser, an interband cascade amplifier, and an external cavity laser having the gain medium are presented.

Abstract: Semiconductor optoelectronic devices such as diode lasers are formed on InP substrates with an active region with an InAsN or InGaAsN electron quantum well layer and a GaAsSb or InGaAsSb hole quantum well layer which form a type II quantum well. The active region may be incorporated in various devices to provide light emission at relatively long wavelengths, including light emitting diodes, amplifiers, surface emitting lasers and edge-emitting lasers.

Abstract: This invention pertains to a method for removing heat from a heat source device and to a heat sink system characterized by a pressure bond having thermal resistance of less than about 5 K/kW-cm2. The method is characterized by the steps of removing heat from a heat source device comprising the steps of placing a heat source device in contact with a heat source and applying a sufficient force to form a pressure bond between the heat source device and the heat sink wherein thermal resistance at the interface between the heat source device and the heat sink after the thermal bond is established is less than about 5 K/kW-cm2. The heat sink system includes a heat source device and a heat sink in contact with the heat source device with thermal resistance at the interface of the heat source device and said heat sink is less than about 5 K/kW-cm2.

Abstract: An apparatus for receiving optical pump radiation having a wavelength &lgr;p and transmitting pump light to an active region. The apparatus includes a first and second reflector, each reflector being reflective at the wavelength &lgr;p, disposed on opposite sides of the active region, where the separation between the reflectors creates a cavity that is resonant at the pump wavelength &lgr;p. The separation distance is preferably about m&lgr;p/2n cos &thgr;, where n is the average index of refraction of the material having an active region, &thgr; is the angle that the pump beam transverses relative the normal of said reflectors, and m is any positive integer. The apparatus provides low cost, high power, optically pumped edge emitting and surface emitting lasers which can be operated at elevated temperatures or power levels. The apparatus further provides mid-IR, high power optically pumped semiconductor lasers with high pump absorbance, long pump wavelength, and a thin active layer.

Abstract: This invention pertains to a method for removing heat from a heat source device and to a heat sink system characterized by a pressure bond having thermal resistance of less than about 5 K/kW-cm2. The method is characterized by the steps of removing heat from a heat source device comprising the steps of placing a heat source device in contact with a heat source and applying a sufficient force to form a pressure bond between the heat source device and the heat sink wherein thermal resistance at the interface between the heat source device and the heat sink after the thermal bond is established is less than about 5 K/kW-cm2. The heat sink system includes a heat source device and a heat sink in contact with the heat source device with thermal resistance at the interface of the heat source device and said heat sink is less than about 5 K/kW-cm2.

Abstract: This invention pertains to a method for removing heat from a heat source device and to a heat sink system characterized by a pressure bond having thermal resistance of less than about 5 K/kW-cm2. The method is characterized by the steps of removing heat from a heat source device comprising the steps of placing a heat source device in contact with a heat source and applying a sufficient force to form a pressure bond between the heat source device and the heat sink wherein thermal resistance at the interface between the heat source device and the heat sink after the thermal bond is established is less than about 5 K/kW-cm2. The heat sink system includes a heat source device and a heat sink in contact with the heat source device with thermal resistance at the interface of the heat source device and said heat sink is less than about 5 K/kW-cm2.

Abstract: An apparatus for receiving optical pump radiation having a wavelength &lgr;p and transmitting pump light to an active region. The apparatus includes a first and second reflector, each reflector being reflective at the wavelength &lgr;p, disposed on opposite sides of the active region, where the separation between the reflectors creates a cavity that is resonant at the pump wavelength &lgr;p. The separation distance is preferably about m&lgr;p/2n cos &thgr;, where n is the average index of refraction of the material having an active region, &thgr; is the angle that the pump beam transverses relative the normal of said reflectors, and m is any positive integer. The apparatus provides low cost, high power, optically pumped edge emitting and surface emitting lasers which can be operated at elevated temperatures or power levels. The apparatus further provides mid-IR, high power optically pumped semiconductor lasers with high pump absorbance, long pump wavelength, and a thin active layer.

Abstract: A pressure clip for contacting a heat sink device to a heat sink by means of a pressure bond having thermal resistance of less than about 5 K/kW/cm2. The pressure clip includes a mounting block, a clamp block; a spacer disposed between the mounting block and the clamp block forming a channel therebetween, support shoulders in the channel for supporting a heat sink, means for securing the clamp block and the spacer to the mounting block, pressure arm disposed above the mounting block, flexible joint for flexibly attaching the pressure arm to the mounting block, pressure screw disposed between the pressure arm and the mounting block for applying pressure to the pressure arm, and a plunger projecting into the channel between the mounting block and the clamp block for transmitting pressure from the pressure arm.

Abstract: The present invention is a method for determining a carrier conductivity-rier mobility spectrum for a semiconductor sample, having the steps of: exposing the semiconductor sample to a range K of discrete magnetic fields k=1,2, . . . K; for each field obtaining a Hall coefficient R.sub.H and a resistivity .rho., and calculating from R.sub.H (B.sub.k) and .sigma.(B.sub.k) experimental conductivity tensor components .sigma..sub.xx.sup.k (exp) and .sigma..sub.xy.sup.k (exp), and slopes of these conductivity tensor components .sigma.'.sub.xx.sup.k (exp) and .sigma.'.sub.xy.sup.k (exp); selecting a trial carrier conductivity-carrier mobility spectrum s.sub.i corresponding to a plurality I of carrier mobilities .mu..sub.i, i=1,2, . . . I; for each B.sub.j, using this trial carrier conductivity-carrier mobility spectrum to calculate conductivity tensor components .sigma..sub.xx.sup.j and .sigma..sub.xy.sup.j, and slopes of the conductivity tensor components .sigma.'.sub.xx.sup.j and .sigma.'.sub.xy.sup.

Abstract: This invention describes a nanometer scale interband lateral resonant tunneling transistor, and the method for producing the same, with lateral geometry, good fanout properties and suitable for incorporation into large-scale integrated circuits. The transistor is of a single gate design and operation is based on resonant tunneling processes in narrow-gap nanostructures which are highly responsive to quantum phenomena. Such quantum-effect devices can have very high density, operate at much higher temperatures and are capable of driving other devices.

Abstract: A type II multiple quantum well, 4 constituent active region, optically clad electrically pumped and optically pumped laser for emitting at a wavelength greater than or equal to about 2.5 microns is disclosed. The active region comprises one or more periods, each period further comprising a barrier layer, a first conduction band layer, a valence band layer and a second conduction band layer.

Abstract: A method and apparatus for producing the conductivity-mobility spectrum of an isotropic semiconductor material, and hence infer the mobility and concentration of carriers in the material. Hall voltage and material conductivity are measured at a plurality of magnetic field strengths, values of the spectrum estimated for each field strength, and the estimates numerically iterated to produce convergent values for the spectrum. In one embodiment, interim selected values of the spectrum are prevented from going negative, which increases the precision of the ultimate convergent values. In another embodiment, the iteration equations employ damping factors to prevent over-correction from one iteration to the next, thus preventing convergent instabilities. The preferred iteration is the Gauss-Seidel recursion.

Abstract: The present invention is an electro-optical modulator having (a) a first semiconductor layer and a second semiconductor layer; (b) a first quantum well layer having a conduction band minimum at an optically active point (typically the L point or the X point), disposed between the first and second semiconductor layers; (c) a second quantum well layer having a conduction band minimum at the optically inactive (at normal incidence) .GAMMA. point, disposed between the first and second semiconductor layers; (d) a spacer layer disposed between the first and second quantum well layers, where the spacer layer has a conduction band minimum that is large enough for establishing quantum confinement in the first quantum well layer at the optically active point and in the second quantum well layer at the .GAMMA. point, but small enough to allow tunnelling between the two layers on a time scale consistent with the desired switching response time.