Patents Represented by Attorney, Agent or Law Firm Eugen E. Pacher
  • Patent number: 6055254
    Abstract: Instead of trying to keep the SLs of a QC laser field free, we "pre-bias" the actual electronic potential by varying the SL period (and hence average composition) so as to achieve an essentially flat profile, on average, of upper and lower minibands, despite the presence of an applied field in the SLs. In one embodiment, in at least a first subset of the QW layers, the thicknesses of the QW layers are varied from QW layer to QW layer so as to increase in the direction of the applied field. In this embodiment, the upper and lower lasing levels are located, in the absence of an applied electric field, each at different energies from layer to layer within the first subset, so that despite the presence of an applied field, the desired flatband condition of the upper and lower minibands is realized.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: April 25, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Federico Capasso, Alfred Yi Cho, Claire F. Gmachl, Albert Lee Hutchinson, Deborah Lee Sivco, Alessandro Tredicucci
  • Patent number: 6055257
    Abstract: A QC laser comprises first and second optical confinement (i.e., cladding) regions, and an In-based, Group III-V compound, QC active region disposed between the confinement regions. At least the first confinement region and the active region having the shape of an elongated mesa. An i-type InP layer covers the sidewalls to provide efficient heat transport and effective low loss mode confinement. A metal layer makes ohmic contact with the top surface of the mesa and a rectifying contact with the i-InP layer.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: April 25, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: James Nelson Baillargeon, Federico Capasso, Alfred Yi Cho, Claire F. Gmachl, Deborah Lee Sivco, Mattias Beck, Jerome Faist
  • Patent number: 6043928
    Abstract: In an optically amplified multi-wavelength optical fiber communication system, deleterious effects due to channel addition/removal can be reduced or avoided if the optical amplifiers are "overpumped", that is to say, the system is selected such that at least 70%, preferably 90% or more, of the pump power that is introduced into the amplifier fiber is unabsorbed in the amplifier fiber.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: March 28, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Kenneth Lee Walker, Frederik Willem Willems
  • Patent number: 6044100
    Abstract: A VCSEL comprises a pair of multi-layered mirrors forming an optical cavity resonator having its axis perpendicular to the layers of the mirrors, an active region disposed within the resonator, and a current guide for directing pumping current through an aperture to generate stimulated emission of radiation which propagates along the resonator axis. A portion of the radiation forms an output signal which emerges through at least one of the mirrors. The current guide includes a lateral injection structure disposed between one of the mirrors and the current aperture. The lateral injection structure comprises at least one relatively thin, highly doped semiconductor layer, each of the highly doped layer(s) being located at a node of the standing wave of the intracavity radiation, at least one lower doped semiconductor layer disposed adjacent each of the highly doped layers (e.g.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: March 28, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: William Scott Hobson, Daryoosh Vakhshoori
  • Patent number: 6023362
    Abstract: In one embodiment, an optical transmitter, which has a modulator disposed between an pair of optical amplifiers, exhibits reduced carrier-to-noise ratio and relatively high powers. In another embodiment, an optical amplifier is disposed between the laser carrier source and the modulator, but the post-modulator amplifier is omitted. Application of the transmitters to analog systems (e.g., CATV) and digital systems is described.
    Type: Grant
    Filed: May 8, 1997
    Date of Patent: February 8, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Kenneth Lee Walker, Frederik Willem Willems
  • Patent number: 6023482
    Abstract: A quantum cascade (QC) laser has a multilayer core region comprising alternating layers of a first and a second semiconductor material, with lattice constants a.sub.1 and a.sub.2, respectively. The first material is selected such that a.sub.1 >a.sub.0, where a, is the lattice constant of the substrate (typically InP), and the second material is selected such that a.sub.2 >a.sub.0. The materials are also selected such that the conduction band discontinuity .DELTA.E.sub.c between the first and second materials is greater than 520 meV in absolute value. The multilayer core comprises a multiplicity of essentially identical multilayer repeat units. The layer thicknesses and materials of the repeat units are selected to substantially provide strain compensation over a repeat unit. QC lasers according to this invention preferably comprise a distributed feedback feature, (e.g.
    Type: Grant
    Filed: January 23, 1998
    Date of Patent: February 8, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Federico Capasso, Alfred Yi Cho, Sung-Nee George Chu, Jerome Faist, Albert Lee Hutchinson, Deborah Lee Sivco
  • Patent number: 6014477
    Abstract: A switching element according to this invention comprises a photostrictive member. Exposing the member to control light results in a dimensional change in the material. This change is utilized for changing the relative position between an optical fiber and another element, exemplarily a further fiber, a corrugated member, or a mirror, such that signal radiation is directed to a predetermined output port. A variety of exemplary switching elements are disclosed, including interferometric, beam-steering, evanescent field and mode conversion switching elements. Disclosed are also optical communication systems that utilize such switching elements, including passive optical networks.
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: January 11, 2000
    Assignees: AT&T Corp., Lucent Technologies Inc.
    Inventors: Bradley Paul Barber, David John Bishop, Nicholas J. Frigo, Peter Ledel Gammel
  • Patent number: 5991061
    Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces refractive index changes, thereby allowing the center wavelength to be altered. A dither signal applied the composite reflector broadens the spectrum of the laser output, thereby reducing SBS in fiber optic systems.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: November 23, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Laura Ellen Adams, Clyde George Bethea, Lars Erik Eskildsen, Gerald Nykolak, Roosevelt People, Tawee Tanbun-Ek
  • Patent number: 5987335
    Abstract: At least the power portion of the transmitter and the front end of the receiver of a base station of a wireless communication system are advantageously co-located with the antenna (or antennae), typically atop a tower or other elevated feature. Such co-location however exposes the electronics to lightning damage. This is avoided by placement of the electronics and antenna into lightning protection apparatus that is transparent to rf radiation during lightning-quiescent conditions but is a Faraday cage during a lightning strike, reverting to the transparent condition at the conclusion of the strike. This is achieved by placement of the electronics and antenna inside a housing that comprises a dielectric chamber filled with ionizable gas in contact with electrodes selected such that, during a lightning strike, current can flow between the electrodes.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: November 16, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: George Knoedl, Jr., Avinoam Kornblit
  • Patent number: 5978135
    Abstract: In an arrangement substantially like an optical isolator, appropriate choice of the composition of the magneto-optic element can result in a variable optical attenuator. The composition is selected to vary in the direction of light propagation, and also is selected such that the magneto-optic element comprises a compensation wall. The compensation wall is movable in response to a change in the temperature of the magneto-optic element, whereby the attenuation of the device is changed.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: November 2, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Robert Ralph Abbott, George Wayne Berkstresser, Charles David Brandle, Jr., Vincent Jerome Fratello, Steven Joy Licht
  • Patent number: 5978397
    Abstract: In a novel tunable semiconductor laser, the lasing transition is a non-resonant tunneling transition, with the frequency of the emitted photon depending on the electrical bias across the multi-period active region of the laser. The laser can be designed to emit in the mid-IR, and can advantageously be used for, e.g., trace gas sensing.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: November 2, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Federico Capasso, Alfred Yi Cho, Jerome Faist, Albert Lee Hutchinson, Carlo Sirtori, Deborah Lee Sivco
  • Patent number: 5977582
    Abstract: A dielectric layer consisting essentially of Ta, Al, oxygen and nitrogen can have advantageous properties that make such a layer useful for thin film capacitors, typically capacitors for Si integrated circuits. For instance, a significantly greater fraction of capacitors according to the invention than of prior art tantalum oxide capacitors can store a charge of 3 .mu.coulomb/cm.sup.2. In a currently preferred embodiment, the dielectric layer has composition Ta.sub.1-y Al.sub.y O.sub.x N.sub.z, with y.about.0.1, x.about.2.4, and z.about.0.02. The dielectric layer can be formed by sputter deposition or any other appropriate deposition technique, e.g., chemical vapor deposition.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: November 2, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Robert McLemore Fleming, Lynn Frances Schneemeyer, Robert Bruce van Dover
  • Patent number: 5972846
    Abstract: Articles according to the invention comprise a superconductive cuprate (e.g., YBa.sub.2 Cu.sub.3 O.sub.7) body containing elongate grains measuring at least about 10 .mu.m along the long axis and having an aspect ratio of at least 10:1. Bodies according to the invention can have relatively high critical current density, as compared to analogous non-textured bodies.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: October 26, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Sungho Jin, Richard Curry Sherwood, Thomas Henry Tiefel
  • Patent number: 5964904
    Abstract: A lead-acid battery according to the invention contains an electrode grid structure that comprises dispersoid-containing lead having relatively high strength and good corrosion resistance. The dispersoid particles exemplarily are selected from the oxides, nitrides and carbides that are substantially insoluble in lead and in sulfuric acid of concentration suitable for use in a lead-acid battery. Significantly, the dispersoid-containing lead has average grain size of at least 20 .mu.m. In consequence of the relatively large grain size, the total length of grain boundaries exposed to electrolyte is relatively small, and corrosion resistance is improved. Exemplary techniques for forming the dispersoid-containing lead are disclosed.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: October 12, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Sungho Jin, Brijesh Vyas, Susan M. Zahurak
  • Patent number: 5966480
    Abstract: The performance of optical fiber Raman devices can be increased by substitution of a broadband reflector (typically a multilayer dielectric mirror) for some of the narrowband reflectors (typically fiber Bragg gratings) that are conventionally used to define the optical cavities of the device. The device exemplarily is a Raman laser or amplifier, and in preferred embodiments a broadband reflector reflects all the Stokes-shifted wavelengths, such that the cavities are defined by the single broadband reflector and by a multiplicity of appropriately selected narrowband reflectors. Optionally the broadband reflector also serves to reflect the pump radiation.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: October 12, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Jane Deborah LeGrange, William Alfred Reed, Kenneth Lee Walker
  • Patent number: 5962883
    Abstract: Disclosed are articles that comprise an oxide layer on a GaAs-based semiconductor body, with metal layers on the oxide and the body facilitating application of an electric field across the oxide layer. The interface between the oxide and the semiconductor body is of device quality. Contrary to teachings of the prior art, the oxide is not essentially pure Ga.sub.2 O.sub.3, but instead has composition Ga.sub.x A.sub.y O.sub.z, where A is an electropositive stabilizer element adapted for stabilizing Ga in the 3+ oxidation state. Furthermore, x.gtoreq.0, z is selected to satisfy the requirement that both Ga and A is substantially fully oxidized and y/(x+y) is greater than 0.1. Stabilizer element A typically is selected from Sc, Y, the rare earth elements and the alkaline earth elements. Articles according to the invention exemplarily comprise a planar enchancement mode MOS-FET with inversion channel. A method of making articles as described above is also disclosed.
    Type: Grant
    Filed: June 8, 1998
    Date of Patent: October 5, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Minghwei Hong, Jueinai Raynien Kwo, Donald Winslow Murphy
  • Patent number: 5936989
    Abstract: The core of the disclosed novel quantum cascade (QC) laser comprises a multiplicity of nominally identical repeat units, with a given repeat unit comprising a superlattice active region and a carrier injector region. Associated with the superlattice active region is an upper and a lower energy miniband, with the lasing transition being the transition from the lower edge of the upper miniband to the upper edge of the lower miniband. The injector facilitates carrier transport from the lower miniband to the upper miniband of the adjacent downstream repeat unit. QC lasers according to this invention can be designed to emit in the infrared, e.g., in the wavelength region 3-15 .mu.m, and can have high power.
    Type: Grant
    Filed: April 29, 1997
    Date of Patent: August 10, 1999
    Assignee: Lucent Technologies, Inc.
    Inventors: Federico Capasso, Alfred Yi Cho, Jerome Faist, Albert Lee Hutchinson, Gaetano Scamarcio, Carlo Sirtori, Deborah Lee Sivco
  • Patent number: 5932905
    Abstract: Ba--Sr--Ti-oxide dielectric material, with at least 60 atomic percent of the total content of the oxide being Ti, can have relatively high dielectric constant K (>40 at 20.degree. C.) and relatively low second order voltage coefficient a.sub.2 of the dielectric constant (a.sub.2 <100 PPM V.sup.2 at 20.degree. C.). In preferred embodiments the dielectric material has nominal composition (BA.sub.x Sr.sub.y Ti.sub.1--x--y)-oxide, with 1--x--y in the range 0.65-0.90, with both x and y greater than or equal to 0.05. Ba, Sr and Ti together typically comprise at least 99 atomic percent of the total metal content of the dielectric material.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: August 3, 1999
    Assignees: Lucent Technologies Inc., Advanced Technology Materials, Inc.
    Inventors: Henry Miles O'Bryan, Jr., Jeffrey Frederick Roeder, Gregory T. Stauf, Roderick Kent Watts
  • Patent number: 5928574
    Abstract: Fiber bow makes mass fusion splicing of optical fiber difficult and this is undesirable. We have found that fiber bow can be significantly reduced if the fiber that is being drawn from a heated optical fiber preform is caused to run through a tubular cooling chamber that extends from the draw furnace, the cooling chamber comprising a tube of inner diameter d.sub.1 <35 mm, preferably <20 mm. In a preferred embodiment the cooling chamber includes an upper cooling chamber of inner diameter d.sub.2 >d.sub.1, with a transition element providing a smooth transition between the two chambers. The cooling chamber desirably is free of turbulence-causing air leaks and/or geometrical features.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: July 27, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Frank Vincent DiMarcello, Richard Garner Huff, Karen S. Kranz, Frederick W. Walz, Jr.
  • Patent number: 5923951
    Abstract: In a method of making a flip-chip bonded GaAs-based opto-electronic device, removal of the GaAs substrate is facilitated by provision of a lattice matched (Al.sub.x Ga.sub.1-x)InP etch stop layer, exemplarily a Ga.sub.0.51 In.sub.0.49 P layer, and use of an etchant that isotropically etches GaAs such that an essentially mirror-like etch stop layer surface results, and that preferably exhibits an etch rate ratio of at least 200:1 for GaAs and the etch stop layer, respectively. Use of the novel substrate removal method can substantially increase device yield, and facilitate manufacture of large device arrays, e.g., arrays of detector/modulator diodes flip-chip bonded to Si CMOS chips.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: July 13, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Keith Wayne Goossen, Jenn-Ming Kuo, Yu-Chi Wang