Patents by Inventor Yeonjoon Park
Yeonjoon Park 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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Publication number: 20140264325Abstract: One aspect of the present invention is a double sided hybrid crystal structure including a trigonal Sapphire wafer containing a (0001) C-plane and having front and rear sides. The Sapphire wafer is substantially transparent to light in the visible and infrared spectra, and also provides insulation with respect to electromagnetic radio frequency noise. A layer of crystalline Si material having a cubic diamond structure aligned with the cubic <111> direction on the (0001) C-plane and strained as rhombohedron to thereby enable continuous integration of a selected (SiGe) device onto the rear side of the Sapphire wafer. The double sided hybrid crystal structure further includes an integrated III-Nitride crystalline layer on the front side of the Sapphire wafer that enables continuous integration of a selected III-Nitride device on the front side of the Sapphire wafer.Type: ApplicationFiled: March 11, 2014Publication date: September 18, 2014Applicant: U.S.A. as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang Hyouk Choi
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Patent number: 8691612Abstract: Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.Type: GrantFiled: March 5, 2012Date of Patent: April 8, 2014Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Hyun-Jung Kim, Sang Hyouk Choi, Glen C. King, Yeonjoon Park, Kunik Lee
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Patent number: 8529825Abstract: A new fabrication method for nanovoids-imbedded bismuth telluride (Bi—Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi—Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.Type: GrantFiled: December 3, 2010Date of Patent: September 10, 2013Assignees: National Institute of Aerospace Associates, The United States of America as represented by the Administration of NASAInventors: Sang-Hyon Chu, Sang H. Choi, Jae-Woo Kim, Yeonjoon Park, James R. Elliott, Glen C. King, Diane M. Stoakley
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Patent number: 8294989Abstract: An optical apparatus includes an optical diffraction device configured for diffracting a predetermined wavelength of incident light onto adjacent optical focal points, and a photon detector for detecting a spectral characteristic of the predetermined wavelength. One of the optical focal points is a constructive interference point and the other optical focal point is a destructive interference point. The diffraction device, which may be a micro-zone plate (MZP) of micro-ring gratings or an optical lens, generates a constructive ray point using phase-contrasting of the destructive interference point. The ray point is located between adjacent optical focal points. A method of generating a densely-accumulated ray point includes directing incident light onto the optical diffraction device, diffracting the selected wavelength onto the constructive interference focal point and the destructive interference focal point, and generating the densely-accumulated ray point in a narrow region.Type: GrantFiled: July 30, 2009Date of Patent: October 23, 2012Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang H. Choi, Glen C. King, James R. Elliott
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Publication number: 20120225513Abstract: Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.Type: ApplicationFiled: March 5, 2012Publication date: September 6, 2012Applicant: U. S.A. as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Hyun-Jung Kim, Sang Hyouk Choi, Glen C. King, Yeonjoon Park, Kunik Lee
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Publication number: 20120224185Abstract: Provided is a method for measuring multi-point interferometric angle changes beginning with an interferometric device capable of measuring at least one main point and at least one reference point. The method includes recording interferometric intensity changes on two or more spots using the main point and the reference point, and determining a sequence having a plurality of peak, local maximas and a plurality of valley, local minimas. The method includes sampling a first, partial sequence and comparing it to a neighboring, partial sequence using a perturbation analysis and additional calculation(s) to compile all phase angle changes for all measured points. Also provided is a computer implemented method to enable nanometer resolution sensitivity in a noisy signal and for characterization of a material in an interferometric device.Type: ApplicationFiled: March 5, 2012Publication date: September 6, 2012Applicant: U.S.A. as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang Hyouk Choi
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Patent number: 8257491Abstract: Growth conditions are developed, based on a temperature-dependent alignment model, to enable formation of cubic group IV, group II-V and group II-VI crystals in the [111] orientation on the basal (0001) plane of trigonal crystal substrates, controlled such that the volume percentage of primary twin crystal is reduced from about 40% to about 0.3%, compared to the majority single crystal. The control of stacking faults in this and other embodiments can yield single crystalline semiconductors based on these materials that are substantially without defects, or improved thermoelectric materials with twinned crystals for phonon scattering while maintaining electrical integrity. These methods can selectively yield a cubic-on-trigonal epitaxial semiconductor material in which the cubic layer is substantially either directly aligned, or 60 degrees-rotated from, the underlying trigonal material.Type: GrantFiled: October 20, 2008Date of Patent: September 4, 2012Assignee: The United States of America, as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang Hyouk Choi, Glen C. King, James R. Elliott
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Publication number: 20120200696Abstract: A lock-in imaging system is configured for detecting a disturbance in air. The system includes an airplane, an interferometer, and a telescopic imaging camera. The airplane includes a fuselage and a pair of wings. The airplane is configured for flight in air. The interferometer is operatively disposed on the airplane and configured for producing an interference pattern by splitting a beam of light into two beams along two paths and recombining the two beams at a junction point in a front flight path of the airplane during flight. The telescopic imaging camera is configured for capturing an image of the beams at the junction point. The telescopic imaging camera is configured for detecting the disturbance in air in an optical path, based on an index of refraction of the image, as detected at the junction point.Type: ApplicationFiled: February 3, 2011Publication date: August 9, 2012Applicant: U.S.A as represented by the Administrator of the N.A.S.A.Inventors: Yeonjoon Park, Sang Hyouk Choi, Glen C. King, James R. Elliott, Albert L. Dimarcantonio
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Patent number: 8226767Abstract: “Super-hetero-epitaxial” combinations comprise epitaxial growth of one material on a different material with different crystal structure. Compatible crystal structures may be identified using a “Tri-Unity” system. New bandgap engineering diagrams are provided for each class of combination, based on determination of hybrid lattice constants for the constituent materials in accordance with lattice-matching equations. Using known bandgap figures for previously tested materials, new materials with lattice constants that match desired substrates and have the desired bandgap properties may be formulated by reference to the diagrams and lattice matching equations. In one embodiment, this analysis makes it possible to formulate new super-hetero-epitaxial semiconductor systems, such as systems based on group IV alloys on c-plane LaF3; group IV alloys on c-plane langasite; Group III-V alloys on c-plane langasite; and group II-VI alloys on c-plane sapphire.Type: GrantFiled: October 20, 2008Date of Patent: July 24, 2012Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang H. Choi, Glen C. King, James R. Elliott
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Patent number: 8217143Abstract: Metal nanoshells are fabricated by admixing an aqueous solution of metal ions with an aqueous solution of apoferritin protein molecules, followed by admixing an aqueous solution containing an excess of an oxidizing agent for the metal ions. The apoferritin molecules serve as bio-templates for the formation of metal nanoshells, which form on and are bonded to the inside walls of the hollow cores of the individual apoferritin molecules. Control of the number of metal atoms which enter the hollow core of each individual apoferritin molecule provides a hollow metal nonparticle, or nanoshell, instead of a solid spherical metal nanoparticle.Type: GrantFiled: July 12, 2007Date of Patent: July 10, 2012Assignees: National Institute of Aerospace Associates, The United States of America as represented by the Administration of NASAInventors: Jae-Woo Kim, Sang H. Choi, Peter T. Lillehei, Sang-Hyon Chu, Yeonjoon Park, Glen C. King, James R. Elliott, Jr.
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Publication number: 20120147379Abstract: Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.Type: ApplicationFiled: December 9, 2010Publication date: June 14, 2012Applicants: Space AdmiInventors: Sang Hyouk Choi, Yeonjoon Park
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Patent number: 8174695Abstract: A spectrometer system includes an array of micro-zone plates (MZP) each having coaxially-aligned ring gratings, a sample plate for supporting and illuminating a sample, and an array of photon detectors for measuring a spectral characteristic of the predetermined wavelength. The sample plate emits an evanescent wave in response to incident light, which excites molecules of the sample to thereby cause an emission of secondary photons. A method of detecting the intensity of a selected wavelength of incident light includes directing the incident light onto an array of MZP, diffracting a selected wavelength of the incident light onto a target focal point using the array of MZP, and detecting the intensity of the selected portion using an array of photon detectors. An electro-optic layer positioned adjacent to the array of MZP may be excited via an applied voltage to select the wavelength of the incident light.Type: GrantFiled: July 23, 2009Date of Patent: May 8, 2012Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Sang H. Choi, Yeonjoon Park, Glen C. King, James R. Elliott
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Patent number: 8094306Abstract: A spectrometer includes a micro-ring grating device having coaxially-aligned ring gratings for diffracting incident light onto a target focal point, a detection device for detecting light intensity, one or more actuators, and an adjustable aperture device defining a circular aperture. The aperture circumscribes a target focal point, and directs a light to the detection device. The aperture device is selectively adjustable using the actuators to select a portion of a frequency band for transmission to the detection device. A method of detecting intensity of a selected band of incident light includes directing incident light onto coaxially-aligned ring gratings of a micro-ring grating device, and diffracting the selected band onto a target focal point using the ring gratings. The method includes using an actuator to adjust an aperture device and pass a selected portion of the frequency band to a detection device for measuring the intensity of the selected portion.Type: GrantFiled: June 19, 2009Date of Patent: January 10, 2012Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Glen C. King, James R. Elliott, Sang H. Choi
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Patent number: 8089677Abstract: A dynamic optical grating device and associated method for modulating light is provided that is capable of controlling the spectral properties and propagation of light without moving mechanical components by the use of a dynamic electric and/or magnetic field. By changing the electric field and/or magnetic field, the index of refraction, the extinction coefficient, the transmittivity, and the reflectivity of the optical grating device may be controlled in order to control the spectral properties of the light reflected or transmitted by the device.Type: GrantFiled: June 8, 2008Date of Patent: January 3, 2012Assignee: The United States of America as represented by the Administrator of the National Aeuronautics and Space AdministrationInventors: Yeonjoon Park, Sang H. Choi, Glen C. King, Sang-Hyon Chu
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Patent number: 8083986Abstract: A novel method to prepare an advanced thermoelectric material has hierarchical structures embedded with nanometer-sized voids which are key to enhancement of the thermoelectric performance. Solution-based thin film deposition technique enables preparation of stable film of thermoelectric material and void generator (voigen). A subsequent thermal process creates hierarchical nanovoid structure inside the thermoelectric material. Potential application areas of this advanced thermoelectric material with nanovoid structure are commercial applications (electronics cooling), medical and scientific applications (biological analysis device, medical imaging systems), telecommunications, and defense and military applications (night vision equipments).Type: GrantFiled: December 4, 2008Date of Patent: December 27, 2011Assignees: National Institute of Aerospace Associates, The United States of America as represented by the Adminstration of NASAInventors: Sang Hyouk Choi, Yeonjoon Park, Sang-Hyon Chu, James R. Elliott, Glen C. King, Jae-Woo Kim, Peter T. Lillehei, Diane M. Stoakley
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Patent number: 8059273Abstract: A spectrometer system includes an optical assembly for collimating light, a micro-ring grating assembly having a plurality of coaxially-aligned ring gratings, an aperture device defining an aperture circumscribing a target focal point, and a photon detector. An electro-optical layer of the grating assembly may be electrically connected to an energy supply to change the refractive index of the electro-optical layer. Alternately, the gratings may be electrically connected to the energy supply and energized, e.g., with alternating voltages, to change the refractive index. A data recorder may record the predetermined spectral characteristic.Type: GrantFiled: July 2, 2009Date of Patent: November 15, 2011Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang H. Choi, Glen C. King, James R. Elliott
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Patent number: 8044294Abstract: New thermoelectric materials comprise highly [111]-oriented twinned group IV alloys on the basal plane of trigonal substrates, which exhibit a high thermoelectric figure of merit and good material performance, and devices made with these materials.Type: GrantFiled: October 20, 2008Date of Patent: October 25, 2011Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Yeonjoon Park, Sang H. Choi, Glen C. King, James R. Elliott, Noel A. Talcott
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Patent number: 8020805Abstract: A new High Altitude Airship (HAA) capable of various extended applications and mission scenarios utilizing inventive onboard energy harvesting and power distribution systems. The power technology comprises an advanced thermoelectric (ATE) thermal energy conversion system. The high efficiency of multiple stages of ATE materials in a tandem mode, each suited for best performance within a particular temperature range, permits the ATE system to generate a high quantity of harvested energy for the extended mission scenarios. When the figure of merit 5 is considered, the cascaded efficiency of the three-stage ATE system approaches an efficiency greater than 60 percent.Type: GrantFiled: July 31, 2007Date of Patent: September 20, 2011Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Sang H. Choi, James R. Elliott, Jr., Glen C. King, Yeonjoon Park, Jae-Woo Kim, Sang-Hyon Chu
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Patent number: 8018815Abstract: An embodiment generally relates to an optical device suitable for use with an optical medium for the storage and retrieval of data. The optical device includes an illumination means for providing a beam of optical radiation of wavelength ? and an optical path that the beam of optical radiation follows. The optical device also includes a diffractive optical element defined by a plurality of annular sections. The plurality of annular sections having a first material alternately disposed with a plurality of annular sections comprising a second material. The diffractive optical element generates a plurality of focal points and densely accumulated ray points with phase contrast phenomena and the optical medium is positioned at a selected focal point or ray point of the diffractive optical element.Type: GrantFiled: June 24, 2009Date of Patent: September 13, 2011Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Sang H. Choi, Yeonjoon Park, Glen C. King, James R. Elliott
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Publication number: 20110117690Abstract: A new fabrication method for nanovoids-imbedded bismuth telluride (Bi—Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi—Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.Type: ApplicationFiled: December 3, 2010Publication date: May 19, 2011Applicants: National Institute of Aerospace Associates, and Space AdministrationInventors: Sang-Hyon Chu, Sang Hyouk Choi, Jae-Woo Kim, Yeonjoon Park, James R. Elliott, JR., Glen C. King, Diane M. Stoakley