Patents by Inventor Robert D. Burnham

Robert D. Burnham has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8510472
    Abstract: The present invention provides methods, devices, and systems for managing message distribution lists. More specifically, the message distribution list may be location-specific and the recipients listed in the list may be dynamically updated based on their detected presence with respect to a particular location. By dynamically updating a message distribution list based on presence information, recipients of the message can be provided with a greater assurance that the messages they receive are locally relevant.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: August 13, 2013
    Assignee: Avaya Inc.
    Inventors: Jeffrie D. Anderson, Robert D. Burnham, Brijen Doshi, Susan K. Love, John V. Rishea, John M. Swanagon
  • Patent number: 8064487
    Abstract: Systems and methods for providing a communication bridge between a physical location and a virtual location are provided. In particular, the presence of a visitor to a physical location is detected, and notification of the presence of a visitor is provided to a user associated with the physical location. The notification may include an identification of the visitor. Following notification, real-time communications between the visitor at the first physical location and the user at the virtual location are established, without requiring entry of a communication address for the virtual office of the user by the visitor.
    Type: Grant
    Filed: April 17, 2006
    Date of Patent: November 22, 2011
    Assignee: Avaya Inc.
    Inventors: James Lee Armstrong, Robert D. Burnham, Cliff L. Howard, Susan K. Love, Paul Michael Madsen, John Vincent Rishea
  • Patent number: 5130771
    Abstract: A heat sink for a semiconductor component of a heat-dissipating and light-radiating semiconductor electronic device. Diamond particles are embedded in a metal matrix to form a composite having a coefficient of thermal expansion which is substantially that of the semiconductor component of the electronic device.
    Type: Grant
    Filed: November 5, 1990
    Date of Patent: July 14, 1992
    Assignee: Amoco Corporation
    Inventors: Robert D. Burnham, Ricardo S. Sussmann
  • Patent number: 5008737
    Abstract: A composite comprised of diamond particles embedded in a metal matrix is a highly satisfactory heat sink material for use with a semiconductor.
    Type: Grant
    Filed: October 11, 1988
    Date of Patent: April 16, 1991
    Assignee: Amoco Corporation
    Inventors: Robert D. Burnham, Ricardo S. Sussmann
  • Patent number: 4901330
    Abstract: An optically pumped laser which includes a laser diode array for generating optically pumped radiation having a uniform intensity distributed over a broad band-width, and a lasant material with an absorption band for receiving radiation within such bandwidth.
    Type: Grant
    Filed: July 20, 1988
    Date of Patent: February 13, 1990
    Assignee: Amoco Corporation
    Inventors: Thomas Wolfram, Bruce A. Vojak, Edward T. Maas, Jr., Robert D. Burnham
  • Patent number: 4882734
    Abstract: A quantum well heterostructure laser has low current density threshold and high T.sub.O values and includes a plurality of contiguous semiconductor layers formed on a substrate wherein one or more the layers form an active region capable of quantization of electron states. The active region is confined by a pair of outer superlattice regions which provide optical confinement and low thermal resistance while preventing the development of antiwaveguiding properties. Many configurations are shown to demonstrate the many forms that the overall laser structure can take and, in particular, the nature of the outer or inner cladding regions of different superlattice geometries and forms.
    Type: Grant
    Filed: March 9, 1988
    Date of Patent: November 21, 1989
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, Robert D. Burnham
  • Patent number: 4875216
    Abstract: A window laser having at least one window region with a transparent waveguide layer optically coupled to an active region generating lightwaves. The waveguide layer is characterized by a broader guided transverse mode for the lightwaves than the active region and may have a thickness which is greater than the active region, a refractive index difference with respect to cladding layers which is less than a refractive index difference between the active region and the cladding layers, or both. The waveguide layer may be coupled to the active region via a transition region characterized by a gradual change in the guide mode width of the lightwaves, such as from a tapered increase in thickness of the waveguide layer in a direction away from the active region.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: October 17, 1989
    Assignee: Xerox Corporation
    Inventors: Robert L. Thornton, Robert D. Burnham
  • Patent number: 4871690
    Abstract: Different diffusion rates can be made operative relative to diffusion disordering in designated areas of a thin active layer or of quantum well feature compared to thermal disordering in other areas thereof where disordering is not desired by the selective placement of migratory defects in a semiconductor support means, such as a semiconductor substrate or semiconductor support layer for supporting subsequently epitaxially deposited semiconductor layers. Such migratory defects as used herein are intended to include impurities and/or other lattice defects initially introduced into the semiconductor support means prior to epitaxial deposition of semiconductor layers constituting the semiconductor structure, wherein at least one of such layers comprises a thin active layer (i.e.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: October 3, 1989
    Assignee: Xerox Corporation
    Inventors: Nick Holonyak, Jr., Robert D. Burnham
  • Patent number: 4857971
    Abstract: A high performance III-V heterostructures exhibiting quantum size effects has been achieved in MODCVD utilizing in situ grown (IV).sub.x (III-V).sub.1-x alloys, where (IV) is a group IV element comprising Si, Ge, C or Sn or admixtures thereof and (III-V) is a group III-V binary, trinary, quaternary or pentad compound or alloy such as, for example, GaAs, AlAs, GaAlAs, GaAlAsP, InGaAlP, InAlAsP or InGaAlAsP. Specific examples are (Si.sub.2).sub.x (GaAs).sub.1-x, which is an alloy that functions as a barrier when grown in situ in a GaAs active region of a heterostructure and (Ge.sub.2).sub.x (GaAs).sub.1-x, which is an alloy that functions as a quantum well when grown in situ in GaAs or GaAlAs active region (e.g. highest refractive index and narrowest bandgap) of a heterostructure. The disclosure further relates to the utilization of a nucleating or catalytic process wherein a small amount of a cluster collector or anchorage component, e.g.
    Type: Grant
    Filed: July 14, 1988
    Date of Patent: August 15, 1989
    Assignee: Xerox Corporation
    Inventor: Robert D. Burnham
  • Patent number: 4839899
    Abstract: The thermalization process is effectively slowed down by reducing the tunneling or communication probability between adjacent quantum wells of a MQW heterostructure laser to increase the number of allowable subbands in the wells and thereby correspondingly increase the range of wavelength tuning of such lasers. This increase of allowable subbands is accomplished by (A) either (1) spatially varying the elemental composition of the wells or barriers or both in order to spatially increase or decrease the energy band from well to well or (2) spatially varying the thickness of the wells or barriers or both in order to spatially increase or decrease the energy band from well to well, or (B) a combination of (1) and (2) of (A).
    Type: Grant
    Filed: March 9, 1988
    Date of Patent: June 13, 1989
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Donald R. Scifres
  • Patent number: 4831630
    Abstract: A laser in which the central portion is provided with current pumping means consisting of an array of current confining stripe contacts to provide a multiple emitter active layer and the end sections of the laser are provided with transparent waveguides. The active layer of this laser can be abruptly stepped along the direction of light propagation, or provided with tapered end couplers, or in any other way made transparent, so that light escapes from the emitters of the active layer of the central portion of the laser into the transparent waveguides at the ends of the laser. The transparent waveguides are of a non-absorbing material of higher bandgap than the central active layer material, or of the same material but otherwise rendered transparent, so that the escaping light strikes the mirror facets and is reflected back, whereby a portion of the reflected light couples back into its emitter and provides the optical feedback for laser operation.
    Type: Grant
    Filed: November 20, 1987
    Date of Patent: May 16, 1989
    Assignee: Xerox Corporation
    Inventors: Donald R. Scifres, William Streifer, Robert D. Burnham
  • Patent number: 4831629
    Abstract: An optically uncoupled laser array is modified at its current confinement geometry to introduce nonuniformity in effective optical cavity width and/or length among the different lasers comprising the laser array. An array laser comprising a plurality of spaced lasing elements with an optical cavity for generating and propagating radiation under lasing conditions with each of the laser elements being optically uncoupled from one another is enhanced by an extended spectral emission linewidth and reduction in temporal coherence. This extended spectral emission linewidth and reduction in temporal coherence is accomplished by changing the gravity gain or loss for at least a majority of the laser elements relative to each other whereby a different longitudinal mode(s) of operation and frequency of operation exist for each such laser element.
    Type: Grant
    Filed: September 1, 1987
    Date of Patent: May 16, 1989
    Assignee: Xerox Corporation
    Inventors: Thomas L. Paoli, Robert D. Burnham, Robert L. Thornton
  • Patent number: 4824798
    Abstract: A thin film bilayer composite source comprises a deposited impurity source layer, e.g. Si or Sb, heavily doped with a diffusion enabling agent, e.g. As, and capped with a passivating layer, e.g. Si.sub.3 N.sub.4, SiO.sub.2, AlN or SiO.sub.x N.sub.y. In a preferred embodiment, a thin film bilayer composite source comprises a Si layer on the surface of said structure vapor deposited at a temperature in excess of 500.degree. C. in the presence of a source of As to hevily dope the layer in the range of 5%-20% atomic weight and a thin cap layer of Si.sub.3 N.sub.4 deposited on the Si layer at a temperature in excess of 500.degree. C. having a thickness only sufficient to prevent the outdiffusion of Ga and As, which thickness may be about 400 .ANG.-700 .ANG.. An important aspect of the employment of this bilayer composite source as a diffusion source for III-V structures is that the composite source is initially deposited at high temperatures, above 500.degree.0 C., i.e.
    Type: Grant
    Filed: November 5, 1987
    Date of Patent: April 25, 1989
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Robert L. Thornton
  • Patent number: 4803691
    Abstract: A diode laser bar producing a linear array of laser beams without lateral superradiance. The laser bar has a double-heterostructure or quantum well structure. Etched channels in the substrate create lateral corrugations in the subsequently deposited layers including the active region. The corrugations alternate between offset groove and plateau regions in the lateral direction but are straight in the longitudinal light propagating direction. Any laterally propagating light is interrupted at steps, between groove and plateau regions, by deflection, scattering or transmission out of the active region. Interruption may also be achieved with a plurality of parallel etched grooves extending in the longitudinal direction. The grooves which cut through the active region present a semiconductor-air interface for reflection and/or scattering of laterally propagating light out of the active region.
    Type: Grant
    Filed: August 28, 1987
    Date of Patent: February 7, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, Hsing Kung, Peter Cross, Robert D. Burnham, William Streifer
  • Patent number: 4799223
    Abstract: A split contact phased array laser comprising a plurality of parallel emitters under phase locked operation and productive of an output beam having a preferred emission wavelength and preferred far field mode of operation. The charge distribution profile in the laser is changed to cause the output beam to deflect and scan in the far field. The improvement in the laser is the provision of at least three independently current pumped segments formed transversely of said emitters wherein at least one of the segments is current pumped above threshold level sufficient to primarily determine the emission wavelength and mode of operation of the laser while the current supplied to the remaining segments is below this level and is varied relative to one another to cause the output beam to deflect and scan in the far field without substantial change to the emission wavelength and mode of operation.
    Type: Grant
    Filed: August 6, 1987
    Date of Patent: January 17, 1989
    Assignee: Xerox Corporation
    Inventors: William Streifer, Robert D. Burnham, Thomas L. Paoli
  • Patent number: 4786918
    Abstract: An incoherent, optically uncoupled laser array for an electro-optic line modulator or a line printer or the like and comprising a plurality of spatial laser emitters characterized by having high power density and a uniform far field emission pattern. Structural means is provided in the array to permit the spacing of the emitters sufficiently close to provide a uniform far field emission pattern without permitting phaselocking between adjacent emitters of the array. The structural means may comprise geometric lateral and diagonal displacement of adjacent optical cavities of the laser elements. Alternatively, the structural means may comprise a plurality of spatially disposed isolation regions extending across the laser array and extending into the laser array a distance sufficient to optically isolate the optical cavities of the laser elements from one another and prevent optical coupling between adjacent laser elements.
    Type: Grant
    Filed: October 1, 1987
    Date of Patent: November 22, 1988
    Assignee: Xerox Corporation
    Inventors: Robert L. Thornton, Henry W. Sang, Jr., Thomas L. Paoli, Robert D. Burnham
  • Patent number: 4771010
    Abstract: A novel energy beam induced layer disordering (EBILD) process is used to (a) locally melt in a scanned pattern regions of a solid state semiconductor heterostructure to produce an alloy of intermediate composition having different optical properties and/or (b) incorporating significantly large amounts of an impurity, present in an encapsulation surface layer of a solid state semiconductor heterostructure, into regions of the heterostructure via absorption of the impurity into liquid alloy melt to form regions having different optical and/or electrical properties and (c) thereafter optionally applying IID to enlarge or extend the disordered/as-grown boundaries of the initially melted region. As a direct write analogue to surface initiated impurity induced disordering (IID), EBILD is a flexible and viable process with high importance for continuous reproducibility and high yield in the fabrication of optoelectronic devices and thin film electronic and optoelectronic circuitry.
    Type: Grant
    Filed: November 21, 1986
    Date of Patent: September 13, 1988
    Assignee: Xerox Corporation
    Inventors: John E. Epler, Robert D. Burnham
  • Patent number: 4730331
    Abstract: A light source comprises a semiconductor laser having a plurality of deposited semiconductor layers including an active region consisting of a plurality of layers forming at least two quantum wells in the active region. The layers immediately adjacent to the active region provide confinement for light generated in one or more optical cavities established in the active region and propagating between end facets of the source. Means, such as in the form of an antireflection (AR) coating, is provided to convert the semiconductor laser into a superluminescent LED source. Further, means is provided to broaden the wavelength spectral emission from the source by rendering the energy levels present in the quantum wells to be at different levels between or among the quantum wells. The resulting output beam has high output intensity and a uniform far field pattern without intensity variation along the beam width particularly useful as a superluminescent LED source for electrooptic line TIR modulators and line printers.
    Type: Grant
    Filed: June 16, 1986
    Date of Patent: March 8, 1988
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Thomas L. Paoli, Robert L. Thornton, Robert A. Sprague
  • Patent number: 4727557
    Abstract: Phased array semiconductor lasers provide fundamental or preferred 1st supermode operation wherein fabrication is accomplished by a single, continuous fabricating process, e.g. MO-CVD or MBE, followed by impurity induced disordering (IID), e.g. utilization of the impurity diffusion technique or the implant/anneal technique as now known in the art. The laser comprising this invention is provided with a relatively thin active region or with a single or multiple quantum well structure in the active region and is fabricated by forming spatially disposed impurity induced disordering regions extending into or penetrating through the active region to form spatially disposed regions capable of providing higher gain compared to adjacent regions not experiencing impurity induced disordering.
    Type: Grant
    Filed: December 30, 1985
    Date of Patent: February 23, 1988
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Robert L. Thornton
  • Patent number: RE33274
    Abstract: A method of converting selected areas of a semiconductor structure into a disordered alloy comprising a well feature epitaxially deposited on a semiconductor support, the well feature comprising at least one first well layer of narrow bandgap material deposited adjacent to at least a second layer of wider bandgap material or interposed between second and third layers of wider bandgap material. The disordered alloy exhibits higher bandgap and lower refractive index properties than the first layer. The method comprises the steps of (1) either placing the structure within a protective environment to prevent the escape of volatile components from the structure during subsequent processing or alternatively, covering the structure with a protective coating to prevent the escape of any elemental component of the structure, (2) heating the structure to a background temperature .[.just.].
    Type: Grant
    Filed: January 31, 1989
    Date of Patent: July 24, 1990
    Assignee: Xerox Corporation
    Inventors: Robert D. Burnham, Noble M. Johnson