Patents by Inventor Doohwan Lee

Doohwan Lee 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: 6690856
    Abstract: An optical waveguide filter including a multi-mode waveguide having a predetermined width, a predetermined length and a predetermined thickness includes a transmitting light source and a photo detector coupled to one side of the multi-mode waveguide; and a transmission line coupled to the other side of the multi-mode waveguide, wherein one hundred percent of an output optical power having a first wavelength from the transmitting light source is transferred to the transmission line, and one hundred percent of an input optical power having a second wavelength from the transmission line is transferred to the photo detector.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: February 10, 2004
    Assignee: Hanbit Information & Communication Co.
    Inventors: Doohwan Lee, Sangsun Lee
  • Publication number: 20030222015
    Abstract: A hydrogen permselective membrane, a method of forming a permselective membrane and an apparatus comprising a permselective membrane, a porous substrate and an optional intermediate layer are described. Using chemical vapor deposition (CVD) at low reactant gas concentration, high permselectivities are achieved with minimal reduction in hydrogen permeance.
    Type: Application
    Filed: June 4, 2002
    Publication date: December 4, 2003
    Applicants: Conoco Inc., Virginia Polytechnic Institute and State University
    Inventors: Shigeo Ted Oyama, Lixiong Zang, Doohwan Lee, Doug S. Jack
  • Publication number: 20030077033
    Abstract: An optical waveguide filter including a multi-mode waveguide having a predetermined width, a predetermined length and a predetermined thickness includes a transmitting light source and a photo detector coupled to one side of the multi-mode waveguide; and a transmission line coupled to the other side of the multi-mode waveguide, wherein one hundred percent of an output optical power having a first wavelength from the transmitting light source is transferred to the transmission line, and one hundred percent of an input optical power having a second wavelength from the transmission line is transferred to the photo detector.
    Type: Application
    Filed: December 7, 2001
    Publication date: April 24, 2003
    Applicant: Doohwan Lee
    Inventors: Doohwan Lee, Sangsun Lee
  • Publication number: 20030053788
    Abstract: An optical attenuator includes a first multi-mode waveguide varying a phase of an optical signal input through an input terminal; first and second single-mode waveguides having an input terminal coupled to an output terminal of the first multi-mode waveguide and varying a phase of the optical signal by a thermo-optic effect by electrodes attached thereto; and a second multi-mode waveguide having an input terminal coupled to an output terminal of the first and second single-mode waveguides and varying a phase of the optical signal, wherein a predetermined optical power distribution obtained by offsetting or adding up a phase varied in the first and second multi-mode waveguides and a phase varied by the thermo-optic effect is transferred to an output terminal of the second multi-mode waveguide.
    Type: Application
    Filed: December 7, 2001
    Publication date: March 20, 2003
    Applicant: Doohwan LEE
    Inventors: Doohwan Lee, Sangsun Lee