Patents by Inventor Rajesh Thapa

Rajesh Thapa 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: 11557872
    Abstract: Fiber optic amplification includes a photonic crystal fiber coupled to a pump laser through a first coupler. The pump laser emits a first electromagnetic radiation wave into the photonic crystal fiber at a first oscillation frequency and a second electromagnetic radiation wave into the photonic crystal fiber at a second oscillation frequency equaling the first oscillation frequency. The first and second electromagnetic radiation waves interact to generate a signal comprising an electromagnetic radiation wave at a third oscillation frequency and an idler comprising a fourth electromagnetic radiation wave at a fourth oscillation frequency to be generated and amplified through parametric amplification. Parametric amplification is achieved by four wave mixing. The photonic crystal fiber emits a parametric output signal based on the four wave mixing. A nonlinear crystal frequency doubles the parametric output signal through second-harmonic generation.
    Type: Grant
    Filed: August 20, 2019
    Date of Patent: January 17, 2023
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: L. Brandon Shaw, Rafael R. Gattass, Rajesh Thapa, Lynda E. Busse, Ishwar D. Aggarwal, Daniel L. Rhonehouse, Jasbinder S. Sanghera, Jason Auxier
  • Patent number: 10843178
    Abstract: Polydentate macrocyclic NHCs (NHC ligands) and related methods are disclosed. Such ligands advantageously facilitate a variety of ligand coordination modes and stabilize oxidation states of metal complexes with a number of coordination environments and shapes. The NHC ligands described herein comprise pendant groups configured to facilitate a variety of reactions including: cis-trans isomerization, proton shuttling and facilitating changes in coordination environments as a result of redox reactions.
    Type: Grant
    Filed: August 20, 2018
    Date of Patent: November 24, 2020
    Assignee: The Board of Trustees of the University of Arkansas
    Inventors: Stefan M. Kilyanek, Rajesh Thapa
  • Patent number: 10649142
    Abstract: Systems and methods are disclosed for splicing crystal fibers to silica glass fibers. Embodiments of the present disclosure provide mechanically stable bonds with negligible optical transmission loss by splicing fibers through a thermally enhanced reaction bonding process at lower temperatures than the melting point of the crystal. In an embodiment, mixing of the materials at elevated temperatures forms a stable intermediary material which enhances strength and reduces the transmission losses.
    Type: Grant
    Filed: June 28, 2019
    Date of Patent: May 12, 2020
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Rajesh Thapa, Rafael R. Gattass, Daniel J. Gibson, Woohong Kim, L. Brandon Shaw, Jasbinder S. Sanghera
  • Publication number: 20200059060
    Abstract: Fiber optic amplification includes a photonic crystal fiber coupled to a pump laser through a first coupler. The pump laser emits a first electromagnetic radiation wave into the photonic crystal fiber at a first oscillation frequency and a second electromagnetic radiation wave into the photonic crystal fiber at a second oscillation frequency equaling the first oscillation frequency. The first and second electromagnetic radiation waves interact to generate a signal comprising an electromagnetic radiation wave at a third oscillation frequency and an idler comprising a fourth electromagnetic radiation wave at a fourth oscillation frequency to be generated and amplified through parametric amplification. Parametric amplification is achieved by four wave mixing. The photonic crystal fiber emits a parametric output signal based on the four wave mixing. A nonlinear crystal frequency doubles the parametric output signal through second-harmonic generation.
    Type: Application
    Filed: August 20, 2019
    Publication date: February 20, 2020
    Inventors: L. Brandon Shaw, Rafael R. Gattass, Rajesh Thapa, Lynda E. Busse, Ishwar D. Aggarwal, Daniel L. Rhonehouse, Jasbinder S. Sanghera, Jason Auxier
  • Publication number: 20190324209
    Abstract: Systems and methods are disclosed for splicing crystal fibers to silica glass fibers. Embodiments of the present disclosure provide mechanically stable bonds with negligible optical transmission loss by splicing fibers through a thermally enhanced reaction bonding process at lower temperatures than the melting point of the crystal. In an embodiment, mixing of the materials at elevated temperatures forms a stable intermediary material which enhances strength and reduces the transmission losses.
    Type: Application
    Filed: June 28, 2019
    Publication date: October 24, 2019
    Inventors: Rajesh Thapa, Rafael R. Gattass, Daniel J. Gibson, Woohong Kim, L. Brandon Shaw, Jasbinder S. Sanghera
  • Patent number: 10338315
    Abstract: Systems and methods are disclosed for splicing crystal fibers to silica glass fibers. Embodiments of the present disclosure provide mechanically stable bonds with negligible optical transmission loss by splicing fibers through a thermally enhanced reaction bonding process at lower temperatures than the melting point of the crystal. In an embodiment, mixing of the materials at elevated temperatures forms a stable intermediary material which enhances strength and reduces the transmission losses.
    Type: Grant
    Filed: October 16, 2017
    Date of Patent: July 2, 2019
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Rajesh Thapa, Rafael R. Gattass, Daniel J. Gibson, Woohong Kim, L. Brandon Shaw, Jasbinder S. Sanghera
  • Publication number: 20190054455
    Abstract: Polydentate macrocyclic NHCs (NHC ligands) and related methods are disclosed. Such ligands advantageously facilitate a variety of ligand coordination modes and stabilize oxidation states of metal complexes with a number of coordination environments and shapes. The NHC ligands described herein comprise pendant groups configured to facilitate a variety of reactions including: cis-trans isomerization, proton shuttling and facilitating changes in coordination environments as a result of redox reactions.
    Type: Application
    Filed: August 20, 2018
    Publication date: February 21, 2019
    Inventors: Stefan M. Kilyanek, Rajesh Thapa
  • Publication number: 20180106968
    Abstract: Systems and methods are disclosed for splicing crystal fibers to silica glass fibers. Embodiments of the present disclosure provide mechanically stable bonds with negligible optical transmission loss by splicing fibers through a thermally enhanced reaction bonding process at lower temperatures than the melting point of the crystal. In an embodiment, mixing of the materials at elevated temperatures forms a stable intermediary material which enhances strength and reduces the transmission losses.
    Type: Application
    Filed: October 16, 2017
    Publication date: April 19, 2018
    Inventors: Rajesh Thapa, Rafael R. Gattass, Daniel J. Gibson, Woohong Kim, L. Brandon Shaw, Jasbinder S. Sanghera