Patents by Inventor Dong Ho Wu

Dong Ho Wu 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: 11024937
    Abstract: Systems and methods are provided for enhancing the terahertz power output of a terahertz beam while increasing its stability and its beam polarity by implementing a pair of pinched ripple electrodes and a small flat section in the middle of each electrode. By using tight control over the design parameters and by exploiting the plasmonic effect and the superradiance effect, systems and methods according to embodiments of the present disclosure can achieve a dramatic improvement in the terahertz output power and beam quality as well as the beam stability.
    Type: Grant
    Filed: May 31, 2019
    Date of Patent: June 1, 2021
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Louis M. Pecora, Christopher Kim
  • Publication number: 20200036076
    Abstract: Systems and methods are provided for enhancing the terahertz power output of a terahertz beam while increasing its stability and its beam polarity by implementing a pair of pinched ripple electrodes and a small flat section in the middle of each electrode. By using tight control over the design parameters and by exploiting the plasmonic effect and the superradiance effect, systems and methods according to embodiments of the present disclosure can achieve a dramatic improvement in the terahertz output power and beam quality as well as the beam stability.
    Type: Application
    Filed: May 31, 2019
    Publication date: January 30, 2020
    Inventors: Dong Ho Wu, Louis M. Pecora, Christopher Kim
  • Patent number: 10393914
    Abstract: Methods and systems for detecting nuclear material concealed within an enclosure are provided. An ionized air density is measured at one or more locations outside of the enclosure. The presence of the concealed nuclear material is detected, for each of the one or more locations, based on a characteristic of the measured ionized air density indicative of concealed nuclear materials.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: August 27, 2019
    Assignees: US Gov't Represented By Secretary Of The Navy Chief Of Naval Research, Temple University Of The Commonwealth System Of Higher Education
    Inventors: Rongjia Tao, Dong Ho Wu
  • Patent number: 10338156
    Abstract: An ultra-sensitivity optical-fiber magneto-optic field sensor includes an input fiber passing optical power from an optical source into the sensor; a polarizer optically coupled to and downstream of the input fiber; an analyzer optically coupled to and downstream of the polarizer; an output fiber passing optical power out of the sensor to a photoreceiver; and a magneto-optic crystal element optically coupled between the polarizer and the analyzer. The ultra-sensitivity optical-fiber magneto-optic field sensor has an optical axis extending between the input and output fibers along which a beam of optical power is transmitted.
    Type: Grant
    Filed: June 1, 2016
    Date of Patent: July 2, 2019
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Anthony Garzarella
  • Patent number: 10094978
    Abstract: Systems and method are provided for producing portable, high power, broadband terahertz emitters based on arrayed terahertz photoconductive antennas. After such an arrayed structure is made, the phase of terahertz signals that are produced by each photoconductive antenna can be adjusted, and the terahertz signals can be added such that the signals are added constructively. Terahertz emitters based on terahertz photoconductive antenna arrays are advantageously small in size and scalable, allowing for terahertz power to be increased by adding more photoconductive antenna arrays.
    Type: Grant
    Filed: June 23, 2016
    Date of Patent: October 9, 2018
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Benjamin Graber
  • Publication number: 20170176548
    Abstract: An ultra-sensitivity optical-fiber magneto-optic field sensor includes an input fiber passing optical power from an optical source into the sensor; a polarizer optically coupled to and downstream of the input fiber; an analyzer optically coupled to and downstream of the polarizer; an output fiber passing optical power out of the sensor to a photoreceiver; and a magneto-optic crystal element optically coupled between the polarizer and the analyzer. The ultra-sensitivity optical-fiber magneto-optic field sensor has an optical axis extending between the input and output fibers along which a beam of optical power is transmitted.
    Type: Application
    Filed: June 1, 2016
    Publication date: June 22, 2017
    Inventors: Dong Ho Wu, Anthony Garzarella
  • Publication number: 20160377803
    Abstract: Systems and method are provided for producing portable, high power, broadband terahertz emitters based on arrayed terahertz photoconductive antennas. After such an arrayed structure is made, the phase of terahertz signals that are produced by each photoconductive antenna can be adjusted, and the terahertz signals can be added such that the signals are added constructively. Terahertz emitters based on terahertz photoconductive antenna arrays are advantageously small in size and scalable, allowing for terahertz power to be increased by adding more photoconductive antenna arrays.
    Type: Application
    Filed: June 23, 2016
    Publication date: December 29, 2016
    Inventors: Dong Ho Wu, Benjamin Graber
  • Patent number: 9494512
    Abstract: Systems and methods for remotely detecting nuclear and non-nuclear materials such as chemical agents and gas-phase explosives are disclosed. Nuclear and non-nuclear materials may be detected by transmitting electromagnetic energy toward a remote target area, collecting scattered electromagnetic energy reflected from the remote target area, analyzing an absorption spectrum of the collected scattered electromagnetic energy, and detecting a presence of at least one nuclear or non-nuclear material in the remote target area based on the analyzed absorption spectrum.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: November 15, 2016
    Inventors: Dong Ho Wu, Rongjia Tao, Benjamin D. Graber
  • Patent number: 9435751
    Abstract: A system and method for detecting and identifying nuclear materials by detecting and measuring positive and negative ions in multiple ion chambers, wherein each ion chamber comprises a different gas, including oxygen, argon, nitrogen, carbon dioxide, and humid air, and one or more ion counters. The ion data can be transmitted to an isotope identification module. The ion data can include a distinctive pattern data of positive-ion production rates and negative-ion production rates generated from the measured positive and negative ions. The isotope identification module can compare the pattern data of positive-ion production rates and negative-ion production rates to an isotope data library, and identify a detected nuclear isotope with the isotope identification module. A display can show the identified detected nuclear isotope; a probability of the presence of the detected nuclear isotope; and a radioactivity of the detected nuclear isotope.
    Type: Grant
    Filed: May 22, 2015
    Date of Patent: September 6, 2016
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Benjamin Graber
  • Publication number: 20150338354
    Abstract: A system and method for detecting and identifying nuclear materials by detecting and measuring positive and negative ions in multiple ion chambers, wherein each ion chamber comprises a different gas, including oxygen, argon, nitrogen, carbon dioxide, and humid air, and one or more ion counters. The ion data can be transmitted to an isotope identification module. The ion data can include a distinctive pattern data of positive-ion production rates and negative-ion production rates generated from the measured positive and negative ions. The isotope identification module can compare the pattern data of positive-ion production rates and negative-ion production rates to an isotope data library, and identify a detected nuclear isotope with the isotope identification module. A display can show the identified detected nuclear isotope; a probability of the presence of the detected nuclear isotope; and a radioactivity of the detected nuclear isotope.
    Type: Application
    Filed: May 22, 2015
    Publication date: November 26, 2015
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Benjamin Graber
  • Publication number: 20150325324
    Abstract: A photoconductive antenna is described that includes a substrate that includes a pair of trenches. Furthermore, a pair of non-parallel electrodes, which can be designed with a chaotic electrode geometry, can each be deposited in one of the trenches, and can be configured to produce chaotic trajectories of incoherent electric currents. Finally, an insulation layer, which can be either a physical electrical insulation layer or an air gap, can be included between each of the pair of non-parallel electrodes and the trench walls. Overall, the thickness of the substrate, the thickness of the trenches, and the thickness of the non-parallel electrodes can each be optimized to produce a coherent terahertz beam.
    Type: Application
    Filed: May 6, 2015
    Publication date: November 12, 2015
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Benjamin Graber, Christopher Kim
  • Patent number: 9177685
    Abstract: A photoconductive antenna is described that includes a substrate that includes a pair of trenches. Furthermore, a pair of non-parallel electrodes, which can be designed with a chaotic electrode geometry, can each be deposited in one of the trenches, and can be configured to produce chaotic trajectories of incoherent electric currents. Finally, an insulation layer, which can be either a physical electrical insulation layer or an air gap, can be included between each of the pair of non-parallel electrodes and the trench walls. Overall, the thickness of the substrate, the thickness of the trenches, and the thickness of the non-parallel electrodes can each be optimized to produce a coherent terahertz beam.
    Type: Grant
    Filed: May 6, 2015
    Date of Patent: November 3, 2015
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Benjamin Graber, Christopher Kim
  • Publication number: 20130038324
    Abstract: An apparatus and system, capable of measuring the magnitude and direction of magnetic fields including an ultra-sensitive, wideband magneto optic (MO) sensor having magneto-optic crystals is disclosed herein. The sensor exploits the Faraday Effect and is based on a polarimetric technique. An ultra sensitivity optical-fiber magneto-optic field sensor measures a magnetic field with minimal perturbation to the field, and the sensor can be used for High-power microwave (HPM) test and evaluation; Diagnosis of radar and RF/microwave devices; Detection/measurement of weak magnetic fields (e.g., magnetic resonance imaging); Characterization of very intense magnetic fields (>100 Tesla, for example rail gun characterization); Detection of very low-frequency magnetic fields; Characterization of a magnetic field over an ultra broad frequency band (DC—2 GHz); Submarine detection; and Submarine underwater communication.
    Type: Application
    Filed: August 11, 2012
    Publication date: February 14, 2013
    Inventors: Dong Ho Wu, Anthony Garzarella
  • Patent number: 8358415
    Abstract: An apparatus, for measuring an applied electrical field and for reducing perturbation to the electrical field being measured, includes a laser integrated into an electro optic crystal sensor head prior to the output fiber. A probe beam is passed along the crystal direction of low birefringence of nearly circular optical indicatrix, rather than one of high EO modulation. The EO crystal is placed between two crossed polarizers and oriented such that a small tilt angle is subtended between its optic axis and the path of the probe beam. Improved optical coupling is achieved by using a large core multimode fiber at the output, to reduce optical insertion losses. A collimating lens emits the intensity modulated laser beam back to a photodetector, where the intensity modulated laser beam is converted to an electrical signal representing both field strength and phase of the electrical field applied to the sensor head.
    Type: Grant
    Filed: July 1, 2010
    Date of Patent: January 22, 2013
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Anthony Garzarella
  • Publication number: 20120305773
    Abstract: Systems and methods for remotely detecting nuclear and non-nuclear materials such as chemical agents and gas-phase explosives are disclosed. Nuclear and non-nuclear materials may be detected by transmitting electromagnetic energy toward a remote target area, collecting scattered electromagnetic energy reflected from the remote target area, analyzing an absorption spectrum of the collected scattered electromagnetic energy, and detecting a presence of at least one nuclear or non-nuclear material in the remote target area based on the analyzed absorption spectrum.
    Type: Application
    Filed: June 1, 2012
    Publication date: December 6, 2012
    Applicants: U.S. Naval Research Laboratory, Temple University of the Commonwealth System of Higher Education
    Inventors: DONG HO WU, RONGJIA TAO, BENJAMIN D. GRABER
  • Publication number: 20120024044
    Abstract: Methods and systems for detecting nuclear material concealed within an enclosure are provided. An ionized air density is measured at one or more locations outside of the enclosure. The presence of the concealed nuclear material is detected, for each of the one or more locations, based on a characteristic of the measured ionized air density indicative of concealed nuclear materials.
    Type: Application
    Filed: February 5, 2010
    Publication date: February 2, 2012
    Applicants: U.S. Naval Research Laboratory, Temple University of the Commonwealth System of Higher Education
    Inventors: Rongjia Tao, Dong Ho Wu
  • Patent number: 7995628
    Abstract: A method and a system are implemented in the fabrication of a portable high power terahertz beam source that can produce a tunable, high power terahertz beam over the frequency from 0.1 THz to 2.5 THz. The terahertz source employs a recycling pump beam method and a beam quality control device. The beam quality control device may or may not be required for a high power terahertz beam generation. In exemplary embodiments, a lithium niobate (LiNbO3) crystal or a lithium niobate crystal doped with 5% magnesium oxide (LiNbO3:MgO) can be used. Other nonlinear optical crystals, including GaSe can be used in place of the LiNbO3 crystal. Through proper alignment of a pump beam, along with recycling a pump beam, high conversion efficiency is achieved, and a high output power beam is produced at terahertz frequencies.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: August 9, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Dong Ho Wu
  • Patent number: 7920263
    Abstract: An apparatus, for measuring an electric field while minimally perturbing the electric field being measured, includes an analyzing stage and a sensor head. The sensor head is optically coupled to the analyzing stage by a laser probe beam transmitted from the analyzing stage. The sensor head includes an electro optic crystal disposed between two gradient index lenses, where the first gradient index lens emits a laser beam transmitted from the analyzing stage to the sensor head, where the electric field is applied and where, the electro optic crystal transforms the laser beam probe into a phase modulated laser beam. The second gradient index lens transmits the phase modulated laser beam back to the analyzing stage, where polarization optics and a photodetector convert the phase modulated laser beam into an electrical signal representing field strength and phase of the electric field.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: April 5, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Dong Ho Wu, Anthony Garzarella
  • Publication number: 20100290487
    Abstract: A method and a system are implemented in the fabrication of a portable high power terahertz beam source that can produce a tunable, high power terahertz beam over the frequency from 0.1 THz to 2.5 THz. The terahertz source employs a recycling pump beam method and a beam quality control device. The beam quality control device may or may not be required for a high power terahertz beam generation. In exemplary embodiments, a lithium niobate (LiNbO3) crystal or a lithium niobate crystal doped with 5% magnesium oxide (LiNbO3:MgO) can be used. Other nonlinear optical crystals, including GaSe can be used in place of the LiNbO3 crystal. Through proper alignment of a pump beam, along with recycling a pump beam, high conversion efficiency is achieved, and a high output power beam is produced at terahertz frequencies.
    Type: Application
    Filed: February 23, 2010
    Publication date: November 18, 2010
    Applicant: US Gov't Represented by the Secretary of the Navy Office of Naval Research (ONR/NRL) Code OOCCIP
    Inventor: Dong Ho Wu
  • Publication number: 20100264904
    Abstract: An apparatus, for measuring an applied electrical field and for reducing perturbation to the electrical field being measured, includes a laser integrated into an electro optic crystal sensor head prior to the output fiber. A probe beam is passed along the crystal direction of low birefringence of nearly circular optical indicatrix, rather than one of high EO modulation. The EO crystal is placed between two crossed polarizers and oriented such that a small tilt angle is subtended between its optic axis and the path of the probe beam. Improved optical coupling is achieved by using a large core multimode fiber at the output, to reduce optical insertion losses. A collimating lens emits the intensity modulated laser beam back to a photodetector, where the intensity modulated laser beam is converted to an electrical signal representing both field strength and phase of the electrical field applied to the sensor head.
    Type: Application
    Filed: July 1, 2010
    Publication date: October 21, 2010
    Applicant: US Gov't Represented by the Secretary of the Navy Office of Naval Research (ONR/NRL) Code OOCCIP
    Inventors: Dong Ho Wu, Anthony Garzarella