Patents by Inventor James S. Sullivan

James S. Sullivan 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: 10191353
    Abstract: An optical switch is disclosed which is electrically activatable through received photon energy. The switch may include a substrate responsive to photon energy that forms an optical excitation signal. First and second electrodes may be disposed on first and second surfaces of the substrate. The substrate may have a characteristic of two-photon absorption to enable electrical conduction through the substrate, the two-photon absorption being enhanced by deep energy levels located in a bandgap between conductance and valence bands of the substrate, which are at least near resonant with the photon energy.
    Type: Grant
    Filed: March 29, 2017
    Date of Patent: January 29, 2019
    Assignee: Lawrence Livermore National Security, LLC
    Inventor: James S. Sullivan
  • Publication number: 20180284565
    Abstract: An optical switch is disclosed which is electrically activatable through received photon energy. The switch may include a substrate responsive to photon energy that forms an optical excitation signal. First and second electrodes may be disposed on first and second surfaces of the substrate. The substrate may have a characteristic of two-photon absorption to enable electrical conduction through the substrate, the two-photon absorption being enhanced by deep energy levels located in a bandgap between conductance and valence bands of the substrate, which are at least near resonant with the photon energy.
    Type: Application
    Filed: March 29, 2017
    Publication date: October 4, 2018
    Inventor: James S. SULLIVAN
  • Patent number: 9240506
    Abstract: A photoconductive semiconductor switch according to one embodiment includes a structure of sintered nanoparticles of a high band gap material exhibiting a lower electrical resistance when excited by light relative to an electrical resistance thereof when not exposed to the light. A method according to one embodiment includes creating a mixture comprising particles, at least one dopant, and at least one solvent; adding the mixture to a mold; forming a green structure in the mold; and sintering the green structure to form a transparent ceramic. Additional system, methods and products are also presented.
    Type: Grant
    Filed: December 8, 2009
    Date of Patent: January 19, 2016
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: Roger W. Werne, James S. Sullivan, Richard L. Landingham
  • Patent number: 9025919
    Abstract: A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces metalized with first metallic layers formed thereon, and encapsulated with a dielectric encapsulation material such as for example epoxy. The first metallic layers are exposed through the encapsulation via encapsulation concavities which have a known contour profile, such as a Rogowski edge profile. Second metallic layers are then formed to line the concavities and come in contact with the first metal layer, to form profiled and metalized encapsulation concavities which mitigate enhancement points at the edges of electrodes matingly seated in the concavities. One or more optical waveguides may also be bonded to the substrate for coupling light into the photo-conductive wafer, with the encapsulation also encapsulating the waveguides.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: May 5, 2015
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: James S. Sullivan, David M. Sanders, Steven A. Hawkins, Stephen A. Sampayan
  • Patent number: 8655125
    Abstract: A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces, and at least one light-input surface. First metallic layers are formed on the electrode-interface surfaces, and one or more optical waveguides having input and output ends are bonded to the substrate so that the output end of each waveguide is bonded to a corresponding one of the light-input surfaces of the photo-conductive substrate. This forms a waveguide-substrate interface for coupling light into the photo-conductive wafer. A dielectric material such as epoxy is then used to encapsulate the photo-conductive substrate and optical waveguide so that only the metallic layers and the input end of the optical waveguide are exposed. Second metallic layers are then formed on the first metallic layers so that the waveguide-substrate interface is positioned under the second metallic layers.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: February 18, 2014
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: James S. Sullivan, David M. Sanders, Steven A. Hawkins, Stephen E. Sampayan
  • Patent number: 8258632
    Abstract: An improved photoconductive switch having a SiC or other wide band gap substrate material with opposing contoured profile cavities which have a contoured profile selected from one of Rogowski, Bruce, Chang, Harrison, and Ernst profiles, and two electrodes with matching contoured-profile convex interface surfaces.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: September 4, 2012
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: James S. Sullivan, Steven A. Hawkins
  • Publication number: 20120082411
    Abstract: A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces, and at least one light-input surface. First metallic layers are formed on the electrode-interface surfaces, and one or more optical waveguides having input and output ends are bonded to the substrate so that the output end of each waveguide is bonded to a corresponding one of the light-input surfaces of the photo-conductive substrate. This forms a waveguide-substrate interface for coupling light into the photo-conductive wafer. A dielectric material such as epoxy is then used to encapsulate the photo-conductive substrate and optical waveguide so that only the metallic layers and the input end of the optical waveguide are exposed. Second metallic layers are then formed on the first metallic layers so that the waveguide-substrate interface is positioned under the second metallic layers.
    Type: Application
    Filed: June 28, 2011
    Publication date: April 5, 2012
    Applicant: Lawrence Livermore National Security, LLC
    Inventors: James S. Sullivan, David M. Sanders, Steven A. Hawkins, Stephen A. Sampayan
  • Patent number: 8125089
    Abstract: An improved photoconductive switch having a SIC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: February 28, 2012
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: George J. Caporaso, Stephen E. Sampayan, James S. Sullivan, David M. Sanders
  • Publication number: 20110133203
    Abstract: A photoconductive semiconductor switch according to one embodiment includes a structure of sintered nanoparticles of a high band gap material exhibiting a lower electrical resistance when excited by light relative to an electrical resistance thereof when not exposed to the light. A method according to one embodiment includes creating a mixture comprising particles, at least one dopant, and at least one solvent; adding the mixture to a mold; forming a green structure in the mold; and sintering the green structure to form a transparent ceramic. Additional system, methods and products are also presented.
    Type: Application
    Filed: December 8, 2009
    Publication date: June 9, 2011
    Inventors: Roger W. Werne, James S. Sullivan, Richard L. Landingham
  • Publication number: 20110101376
    Abstract: An improved photoconductive switch having a SIC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.
    Type: Application
    Filed: November 23, 2010
    Publication date: May 5, 2011
    Applicant: Lawrence Livermore National Security, LLC
    Inventors: George J. Caporaso, Stephen E. Sampayan, James S. Sullivan, David M. Sanders
  • Patent number: 7893541
    Abstract: An improved photoconductive switch having a SiC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: February 22, 2011
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: George J. Caporaso, Stephen E. Sampayan, James S. Sullivan, David M. Sanders
  • Patent number: 5666385
    Abstract: The instantaneous V.sub.co signal on a charging capacitor is sampled and the charge voltage on capacitor C.sub.o is captured just prior to its discharge into the first stage of magnetic modulator. The captured signal is applied to an averaging circuit with a long time constant and to the positive input terminal of a differential amplifier. The averaged V.sub. co signal is split between a gain stage (G=0.975) and a feedback stage that determines the slope of the voltage ramp applied to the high speed comparator. The 97.5% portion of the averaged V.sub.co signal is applied to the negative input of a differential amplifier gain stage (G=10). The differential amplifier produces an error signal by subtracting 97.5% of the averaged V.sub.co signal from the instantaneous value of sampled V.sub.co signal and multiplying the difference by ten. The resulting error signal is applied to the positive input of a high speed comparator.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: September 9, 1997
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: James S. Sullivan, Don G. Ball