Patents by Inventor Qingyu (Tom) Li

Qingyu (Tom) Li 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: 11016441
    Abstract: A two-step optimization process is utilized to define an optimal phase profile for a LCoS spatial light modulator. The two-step optimization process first utilizes a nonlinear constrained optimization (NCO) program to determine the specific parameters required to obtain an optimal phase profile (hologram), where the “optimal phase profile” is typically defined as that profile which achieves maximum diffraction efficiency for optical switching. Following this first step, phase scaling (and perhaps an adjustment in the number of pixels per period) is employed to slightly modify the values of the optimal phase profile to effectively suppress crosstalk peaks. If any orders still exhibit an unacceptable level of crosstalk, these orders are then subtracted from the phase profile to create the final design.
    Type: Grant
    Filed: February 18, 2019
    Date of Patent: May 25, 2021
    Assignee: II-VI Delaware, Inc.
    Inventors: Kun Gao, Jack R. Kelly, Helen Chen, Guomin Jiang, Xinran Wang, Lixin (Lawrence) Wang, Qingyu (Tom) Li, Haiji J. Yuan
  • Publication number: 20200264558
    Abstract: A two-step optimization process is utilized to define an optimal phase profile for a LCoS spatial light modulator. The two-step optimization process first utilizes a nonlinear constrained optimization (NCO) program to determine the specific parameters required to obtain an optimal phase profile (hologram), where the “optimal phase profile” is typically defined as that profile which achieves maximum diffraction efficiency for optical switching. Following this first step, phase scaling (and perhaps an adjustment in the number of pixels per period) is employed to slightly modify the values of the optimal phase profile to effectively suppress crosstalk peaks. If any orders still exhibit an unacceptable level of crosstalk, these orders are then subtracted from the phase profile to create the final design.
    Type: Application
    Filed: February 18, 2019
    Publication date: August 20, 2020
    Applicant: II-VI Delaware, Inc.
    Inventors: Kun Gao, Jack R. Kelly, Helen Chen, Guomin Jiang, Xinran Wang, Lixin (Lawrence) Wang, Qingyu (Tom) Li, Haiji J. Yuan
  • Patent number: 6765635
    Abstract: An achromatic half wave plate includes a first twisted nematic liquid crystal layer, a second twisted nematic liquid crystal layer, and a uniaxial half wave plate between the first twisted nematic liquid crystal layer and the second twisted nematic liquid crystal layer. In one embodiment the first twisted nematic liquid crystal layer and the second twisted nematic liquid crystal layer have an identical twist angle of 135 degrees. The optic axis at the entrance of the first twisted nematic liquid crystal layer is substantially orthogonal to the optic axis at the exit of the second twisted nematic liquid crystal layer.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: July 20, 2004
    Assignee: CoAdna Photonics, Inc.
    Inventors: Jack R. Kelly, Haiji J. Yuan, Qingyu (Tom) Li
  • Patent number: 6747774
    Abstract: The invention includes an apparatus for processing an input optical beam. The apparatus has at least one variable optical element to dynamically alter the polarization state of an optical beam to form a polarization-altered optical beam, wherein the polarization-altered optical beam includes elliptical polarization. At least one wave plate operates on the polarization-altered optical beam, each wave plate has a selected retardation, order of retardation, and orientation. A polarization analyzer, operating in conjunction with the at least one variable optical element and wave plate, alters the transmitted amplitude of the polarization-altered optical beam as a function of wavelength, and thereby produces an output optical beam with transmitted amplitude adjusted as a function of wavelength.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: June 8, 2004
    Assignee: CoAdna Photonics, Inc.
    Inventors: Jack R. Kelly, Haiji J. Yuan, Qingyu (Tom) Li, Hudson Washburn
  • Publication number: 20030016445
    Abstract: The invention includes an apparatus for processing an input optical beam. The apparatus has at least one variable optical element to dynamically alter the polarization state of an optical beam to form a polarization-altered optical beam, wherein the polarization-altered optical beam includes elliptical polarization. At least one wave plate operates on the polarization-altered optical beam, each wave plate has a selected retardation, order of retardation, and orientation. A polarization analyzer, operating in conjunction with the at least one variable optical element and wave plate, alters the transmitted amplitude of the polarization-altered optical beam as a function of wavelength, and thereby produces an output optical beam with transmitted amplitude adjusted as a function of wavelength.
    Type: Application
    Filed: December 5, 2001
    Publication date: January 23, 2003
    Inventors: Jack R. Kelly, Haiji J. Yuan, Qingyu (Tom) Li, Hudson Washburn