Patents by Inventor Kyuman Cho

Kyuman Cho 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: 8405835
    Abstract: The present invention relates to a scanning microscope using a heterodyne interferometer, which can be used for mapping or imaging complex optical parameters such as physical structures and material properties of a sample under test. The heterodyne interferometer is designed to provide in- and quadrature-phase interference signal which can be used for extracting the phase and amplitude change induced on the probe beam. The phase and the amplitude of the probe beam, which is reflected from or transmitted through the sample, are modified by the physical structures and material properties of the sample. Therefore, by scanning the probe beam, local variations of the phase and amplitude can be mapped, and, thereby, three-dimensional microscopic physical structures and material properties can be imaged by processing the phase and amplitude values.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: March 26, 2013
    Assignee: Industry-University Cooperation Foundation Sogang University
    Inventors: Kyuman Cho, Kang-Hyuk Kwon
  • Patent number: 8289525
    Abstract: Disclosed herein is an apparatus and method which is capable of accurately measuring surface status, such as a minute variation in height (the height difference), a protrusion, a depression, surface damage and/or surface roughness, at each point on the surface of the object to be measured in an optical manner. In particular, the present invention provides an optical surface measuring apparatus and method which is capable of accurately measuring the minute surface status of the object to be measured using both a signal from an interferometer and a Focus Error (FE) signal from a Position Sensitive Detector (PSD) in order to overcome the 2?-ambiguity of the conventional interferometers and the limitation of the Focus Error (FE) signal.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: October 16, 2012
    Assignee: Industry-University Cooperation Foundation Sogang University
    Inventors: Seung-Yop Lee, Kyoung Up Kim, Jae Hyun Kim, Kyuman Cho, Young Kyu Park
  • Publication number: 20100220337
    Abstract: Disclosed herein is an apparatus and method which is capable of accurately measuring surface status, such as a minute variation in height (the height difference), a protrusion, a depression, surface damage and/or surface roughness, at each point on the surface of the object to be measured in an optical manner. In particular, the present invention provides an optical surface measuring apparatus and method which is capable of accurately measuring the minute surface status of the object to be measured using both a signal from an interferometer and an FE signal from a Position Sensitive Detector (PSD) in order to overcome the 2?-ambiguity of the conventional interferometers and the limitation of the FE signal.
    Type: Application
    Filed: September 17, 2009
    Publication date: September 2, 2010
    Inventors: Seung-Yop LEE, Kyoung Up Kim, Jae Hyun Kim, Kyuman Cho, Young Kyu Park
  • Publication number: 20100128279
    Abstract: The present invention relates to a scanning microscope using a heterodyne interferometer, which can be used for mapping or imaging complex optical parameters such as physical structures and material properties of a sample under test. The heterodyne interferometer is designed to provide in- and quadrature-phase interference signal which can be used for extracting the phase and amplitude change induced on the probe beam. The phase and the amplitude of the probe beam, which is reflected from or transmitted through the sample, are modified by the physical structures and material properties of the sample. Therefore, by scanning the probe beam, local variations of the phase and amplitude can be mapped, and, thereby, three-dimensional microscopic physical structures and material properties can be imaged by processing the phase and amplitude values.
    Type: Application
    Filed: January 29, 2010
    Publication date: May 27, 2010
    Applicant: Industry-University Cooperation Foundation Sogang University
    Inventors: Kyuman CHO, Kang-Hyuk KWON
  • Publication number: 20050117904
    Abstract: The present invention relates to the optical transmitter, receiver and application apparatus thereof for OWLL (Optical WireLess Link) which transmits and receives the optical signals through the free space and FSON (Free Space Optical Network) system using OWLL. Photonic devices such as laser diode and photo detector and integrated circuits for driving the photonic devices are formed directly into a single chip and the chip is assembled with optical instrument which is manufactured as a standardized optical module. Then, the optical transmitter, receiver and application apparatus thereof becomes small, light, cost-effective, multi-functional and reliable.
    Type: Application
    Filed: August 1, 2001
    Publication date: June 2, 2005
    Inventors: Youngwan Choi, Kyuman Cho
  • Publication number: 20040149891
    Abstract: Infrared ray detecting board which is able to observe the intensity, size and shape of the laser light from the transmitter and to separate the laser light of the transmitter from the external infrared rays to confirm the arriving position of the laser light to the receiver at the transmitter side directly, and LED indicator for corresponding the center of the laser light to the photo-detecting region of the receiver are provided. Moreover, various alignment methods using such devices and an alignment device having removable motor are provided.
    Type: Application
    Filed: March 17, 2004
    Publication date: August 5, 2004
    Inventors: Kyuman Cho, Youngwan Choi, Heeseong Jeong
  • Publication number: 20040091270
    Abstract: The present invention relates to the optical transmitter, receiver and application apparatus thereof for OWLL (Optical WireLess Link) which transmits and receives the optical signals through the free space and FSON (Free Space Optical Network) system using OWLL. Photonic devices such as laser diode and photo detector and electronics for driving the photonic devices are formed directly on a single printed circuit board as a standardized module and the PCB is assembled with optical instrument which is also manufactured as a standardized optical module. Then, the optical transmitter, receiver and application apparatus thereof becomes small, light, cost-effective, multi-functional and reliable.
    Type: Application
    Filed: July 31, 2003
    Publication date: May 13, 2004
    Inventors: Youngwan Choi, Kyuman Cho
  • Publication number: 20020171897
    Abstract: A plurality of short-range optical wireless links are coupled together to form a high-speed, customized subscriber network. Each of the plurality of short-range optical wireless links has a short-range optical transmitter and a short-range optical receiver. These devices are separated by a distance over which fading of received optical power caused by atmospheric turbulence can be neglected. In an embodiment, the subscriber network includes at least one medium-range optical wireless link for communicating over a distance up to 500 meters. In an embodiment, the subscriber network includes at least one long-range optical wireless link for communicating over a distance greater than 500 meters.
    Type: Application
    Filed: July 20, 2001
    Publication date: November 21, 2002
    Inventors: Kyuman Cho, Young-Wan Choi