Patents by Inventor George T. Wang
George T. Wang 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: 12133755Abstract: Techniques are provided for x-ray image data monitoring and signaling for patient safety. A methodology implementing the techniques according to an embodiment includes integrating energy associated with a received x-ray pulse at an array of pixels. The method also includes multiplexing a readout of the integrated energy from the array of pixels, as analog signals, into channels, and performing analog to digital conversion of the analog signals of the channels into digital signals. The method further includes generating an error indicator in response to determining that a calculated mean of the digital signals is either greater than an upper threshold value associated with saturation or less than a lower threshold value associated with underexposure. The method further includes transmitting the error indicator over a Universal Serial Bus, to an imaging system, to terminate transmission of further x-ray pulses.Type: GrantFiled: December 14, 2021Date of Patent: November 5, 2024Assignee: BAE Systems Imaging Solutions Inc.Inventors: Stanley K. Searing, Kwang Bo Cho, Hung T. Do, Stephen W. Mims, Marc K. Thacher, Bruce E. Willy, Glen L. Collier, Douglas W. Teeter, George Y. Wang
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Publication number: 20240162859Abstract: In one aspect, the disclosure relates to a super high frequency (SHF) or extremely high frequency (EHF) bulk acoustic resonator that includes a nanostructure, wherein the nanostructure includes a substrate, a three-dimensional structure disposed on the substrate, wherein the three-dimensional structure includes a planar structure including at least one nanocomponent and a matrix material contacting the nanocomponent on at least one side, the matrix material including an SiGe alloy or Ge. The disclosed bulk acoustic resonator operates at frequencies of from about 100 MHz to about 100 GHz, is capable of self-amplification upon application of direct current or voltage, and has a Q factor amplification exceeding 1. Also disclosed are methods for amplification of mechanical resonance in the disclosed bulk acoustic resonators and devices incorporating the bulk acoustic resonators.Type: ApplicationFiled: November 27, 2023Publication date: May 16, 2024Inventors: Roozbeh TABRIZIAN, Kevin S. JONES, George T. WANG
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Patent number: 11424135Abstract: In a method of atomic precision advanced manufacturing (APAM), an atomic or molecular resist layer on a substrate surface is selectively depassivated by locally exciting the substrate surface with an optical beam effective to eject adsorbed atoms or molecules from the substrate surface. The substrate surface is further processed by exposing it to a precursor gas, decomposing the precursor gas to release a dopant, and incorporating the dopant into the substrate surface.Type: GrantFiled: February 23, 2021Date of Patent: August 23, 2022Assignee: National Technology & Engineering Solutions of Sandia, LLCInventors: Aaron Michael Katzenmeyer, Shashank Misra, Andrew David Baczewski, Evan Michael Anderson, George T. Wang, Daniel Robert Ward
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Patent number: 11222950Abstract: A layered heterostructure, comprising alternating layers of different semiconductors, wherein one of the atom species of one of the semiconductors has a faster diffusion rate along an oxidizing interface than an atom species of the other semiconductor at an oxidizing temperature, can be used to fabricate embedded nanostructures with arbitrary shape. The result of the oxidation will be an embedded nanostructure comprising the semiconductor having slower diffusing atom species surrounded by the semiconductor having the higher diffusing atom species. The method enables the fabrication of low- and multi-dimensional quantum-scale embedded nanostructures, such as quantum dots (QDs), toroids, and ellipsoids.Type: GrantFiled: April 20, 2020Date of Patent: January 11, 2022Assignees: National Technology & Engineering Solutions of Sandia, LLC, University of Florida Research Foundation, IncorporatedInventors: George T. Wang, Keshab R. Sapkota, Kevin S. Jones, Emily M. Turner
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Publication number: 20200365689Abstract: A layered heterostructure, comprising alternating layers of different semiconductors, wherein one of the atom species of one of the semiconductors has a faster diffusion rate along an oxidizing interface than an atom species of the other semiconductor at an oxidizing temperature, can be used to fabricate embedded nanostructures with arbitrary shape. The result of the oxidation will be an embedded nanostructure comprising the semiconductor having slower diffusing atom species surrounded by the semiconductor having the higher diffusing atom species. The method enables the fabrication of low- and multi-dimensional quantum-scale embedded nanostructures, such as quantum dots (QDs), toroids, and ellipsoids.Type: ApplicationFiled: April 20, 2020Publication date: November 19, 2020Inventors: George T. Wang, Keshab R. Sapkota, Kevin S. Jones, Emily M. Turner
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Publication number: 20160365705Abstract: A method for tuning the lasing wavelength of a semiconductor nano/microlaser uses mechanical strain to change the bandgap of the semiconductor material and the lasing wavelength. The method enables broad, dynamic, and reversible spectral tuning of single nano/microlasers with subnanometer resolution.Type: ApplicationFiled: June 11, 2015Publication date: December 15, 2016Inventors: George T. Wang, Sheng Liu
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Patent number: 9276382Abstract: Quantum-size-controlled photoelectrochemical (QSC-PEC) etching provides a new route to the precision fabrication of epitaxial semiconductor nanostructures in the sub-10-nm size regime. For example, quantum dots (QDs) can be QSC-PEC-etched from epitaxial InGaN thin films using narrowband laser photoexcitation, and the QD sizes (and hence bandgaps and photoluminescence wavelengths) are determined by the photoexcitation wavelength.Type: GrantFiled: February 17, 2015Date of Patent: March 1, 2016Assignee: Sandia CorporationInventors: Arthur J. Fischer, Jeffrey Y. Tsao, Jonathan J. Wierer, Jr., Xiaoyin Xiao, George T. Wang
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Publication number: 20150270136Abstract: Quantum-size-controlled photoelectrochemical (QSC-PEC) etching provides a new route to the precision fabrication of epitaxial semiconductor nanostructures in the sub-10-nm size regime. For example, quantum dots (QDs) can be QSC-PEC-etched from epitaxial InGaN thin films using narrowband laser photoexcitation, and the QD sizes (and hence bandgaps and photoluminescence wavelengths) are determined by the photoexcitation wavelength.Type: ApplicationFiled: February 17, 2015Publication date: September 24, 2015Inventors: Arthur J. Fischer, Jeffrey Y. Tsao, Jonathan J. Wierer, JR., Xiaoyin Xiao, George T. Wang
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Patent number: 9020005Abstract: A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission center wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal center wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.Type: GrantFiled: February 3, 2014Date of Patent: April 28, 2015Assignee: Sandia CorporationInventors: Jeremy B. Wright, Igal Brener, Ganapathi S. Subramania, George T. Wang, Qiming Li
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Patent number: 8932403Abstract: A method for forming a surface-textured single-crystal film layer by growing the film atop a layer of microparticles on a substrate and subsequently selectively etching away the microparticles to release the surface-textured single-crystal film layer from the substrate. This method is applicable to a very wide variety of substrates and films. In some embodiments, the film is an epitaxial film that has been grown in crystallographic alignment with respect to a crystalline substrate.Type: GrantFiled: May 23, 2011Date of Patent: January 13, 2015Assignee: Sandia CorporationInventors: Qiming Li, George T. Wang
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Patent number: 8895337Abstract: A top-down method of fabricating vertically aligned Group III-V micro- and nanowires uses a two-step etch process that adds a selective anisotropic wet etch after an initial plasma etch to remove the dry etch damage while enabling micro/nanowires with straight and smooth faceted sidewalls and controllable diameters independent of pitch. The method enables the fabrication of nanowire lasers, LEDs, and solar cells.Type: GrantFiled: January 17, 2013Date of Patent: November 25, 2014Assignee: Sandia CorporationInventors: George T. Wang, Qiming Li
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Publication number: 20140219306Abstract: A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission centre wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal centre wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.Type: ApplicationFiled: February 3, 2014Publication date: August 7, 2014Applicant: Sandia CorporationInventors: Jeremy B. Wright, Igal Brener, Ganapathi S. Subramania, George T. Wang, Qiming Li
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Patent number: 8785905Abstract: A temperature stable (color and efficiency) III-nitride based amber (585 nm) light-emitting diode is based on a novel hybrid nanowire-planar structure. The arrays of GaN nanowires enable radial InGaN/GaN quantum well LED structures with high indium content and high material quality. The high efficiency and temperature stable direct yellow and red phosphor-free emitters enable high efficiency white LEDs based on the RGYB color-mixing approach.Type: GrantFiled: January 17, 2013Date of Patent: July 22, 2014Assignee: Sandia CorporationInventors: George T. Wang, Qiming Li, Jonathan J. Wierer, Jr., Daniel Koleske
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Patent number: 8741748Abstract: Group III-nitride epilayers can be grown directly on copper substrates using intermediate passivation layers. For example, single crystalline c-plane GaN can be grown on Cu (110) substrates with MOCVD. The growth relies on a low temperature AlN passivation layer to isolate any alloying reaction between Ga and Cu.Type: GrantFiled: March 15, 2013Date of Patent: June 3, 2014Assignee: Sandia CorporationInventors: Qiming Li, George T. Wang, Jeffrey T. Figiel
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Patent number: 8653500Abstract: A volume-scalable, high-brightness, electrically driven visible light source comprises a three-dimensional photonic crystal (3DPC) comprising one or more direct bandgap semiconductors. The improved light emission performance of the invention is achieved based on the enhancement of radiative emission of light emitters placed inside a 3DPC due to the strong modification of the photonic density-of-states engendered by the 3DPC.Type: GrantFiled: September 13, 2011Date of Patent: February 18, 2014Assignee: Sandia CorporationInventors: Ganapathi Subramania, Arthur J. Fischer, George T. Wang, Qiming Li
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Patent number: 8425681Abstract: A method for growing low-dislocation-density material atop a layer of the material with an initially higher dislocation density using a monolayer of spheroidal particles to bend and redirect or directly block vertically propagating threading dislocations, thereby enabling growth and coalescence to form a very-low-dislocation-density surface of the material, and the structures made by this method.Type: GrantFiled: February 18, 2009Date of Patent: April 23, 2013Assignee: Sandia CorporationInventors: George T. Wang, Qiming Li
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Patent number: 7745315Abstract: A method for forming vertically oriented, crystallographically aligned nanowires (nanocolumns) using monolayer or submonolayer quantities of metal atoms to form uniformly sized metal islands that serve as catalysts for MOCVD growth of Group III nitride nanowires.Type: GrantFiled: October 3, 2007Date of Patent: June 29, 2010Assignee: Sandia CorporationInventors: George T. Wang, Qiming Li, J. Randall Creighton
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Patent number: 7670933Abstract: A method for growing high quality, nonpolar Group III nitrides using lateral growth from Group III nitride nanowires. The method of nanowire-templated lateral epitaxial growth (NTLEG) employs crystallographically aligned, substantially vertical Group III nitride nanowire arrays grown by metal-catalyzed metal-organic chemical vapor deposition (MOCVD) as templates for the lateral growth and coalescence of virtually crack-free Group III nitride films. This method requires no patterning or separate nitride growth step.Type: GrantFiled: October 3, 2007Date of Patent: March 2, 2010Assignee: Sandia CorporationInventors: George T. Wang, Qiming Li, J. Randall Creighton
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Patent number: 7449404Abstract: A method for improving Mg doping of Group III-N materials grown by MOCVD preventing condensation in the gas phase or on reactor surfaces of adducts of magnesocene and ammonia by suitably heating reactor surfaces between the location of mixing of the magnesocene and ammonia reactants and the Group III-nitride surface whereon growth is to occur.Type: GrantFiled: April 26, 2005Date of Patent: November 11, 2008Assignee: Sandia CorporationInventors: J. Randall Creighton, George T. Wang