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).
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Patent number: 10191353Abstract: 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: GrantFiled: March 29, 2017Date of Patent: January 29, 2019Assignee: Lawrence Livermore National Security, LLCInventor: James S. Sullivan
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Publication number: 20180284565Abstract: 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: ApplicationFiled: March 29, 2017Publication date: October 4, 2018Inventor: James S. SULLIVAN
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Patent number: 9240506Abstract: 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: GrantFiled: December 8, 2009Date of Patent: January 19, 2016Assignee: Lawrence Livermore National Security, LLCInventors: Roger W. Werne, James S. Sullivan, Richard L. Landingham
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Patent number: 9025919Abstract: 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: GrantFiled: October 22, 2012Date of Patent: May 5, 2015Assignee: Lawrence Livermore National Security, LLCInventors: James S. Sullivan, David M. Sanders, Steven A. Hawkins, Stephen A. Sampayan
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Patent number: 8655125Abstract: 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: GrantFiled: June 28, 2011Date of Patent: February 18, 2014Assignee: Lawrence Livermore National Security, LLCInventors: James S. Sullivan, David M. Sanders, Steven A. Hawkins, Stephen E. Sampayan
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Patent number: 8258632Abstract: 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: GrantFiled: June 28, 2011Date of Patent: September 4, 2012Assignee: Lawrence Livermore National Security, LLCInventors: James S. Sullivan, Steven A. Hawkins
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Publication number: 20120082411Abstract: 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: ApplicationFiled: June 28, 2011Publication date: April 5, 2012Applicant: Lawrence Livermore National Security, LLCInventors: James S. Sullivan, David M. Sanders, Steven A. Hawkins, Stephen A. Sampayan
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Patent number: 8125089Abstract: 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: GrantFiled: November 23, 2010Date of Patent: February 28, 2012Assignee: Lawrence Livermore National Security, LLCInventors: George J. Caporaso, Stephen E. Sampayan, James S. Sullivan, David M. Sanders
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Publication number: 20110133203Abstract: 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: ApplicationFiled: December 8, 2009Publication date: June 9, 2011Inventors: Roger W. Werne, James S. Sullivan, Richard L. Landingham
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Publication number: 20110101376Abstract: 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: ApplicationFiled: November 23, 2010Publication date: May 5, 2011Applicant: Lawrence Livermore National Security, LLCInventors: George J. Caporaso, Stephen E. Sampayan, James S. Sullivan, David M. Sanders
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Patent number: 7893541Abstract: 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: GrantFiled: October 24, 2006Date of Patent: February 22, 2011Assignee: Lawrence Livermore National Security, LLCInventors: George J. Caporaso, Stephen E. Sampayan, James S. Sullivan, David M. Sanders
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Patent number: 5666385Abstract: 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: GrantFiled: November 15, 1994Date of Patent: September 9, 1997Assignee: The United States of America as represented by the United States Department of EnergyInventors: James S. Sullivan, Don G. Ball