Patents by Inventor Kilhun Koo

Kilhun Koo 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: 7619727
    Abstract: The present invention relates to a light wavelength and intensity measuring device. The device automatically measures a center wavelength of the light source and an intensity of the light corresponding to the center wavelength by using a main photodetector, at least one optical filter, and at least one sub photodetector when the light source is connected to the device. The main photodetector detects the intensity of the light applied by the light source, the optical filter transmits the light corresponding to a prediscriminated transmission wavelength, and the sub photodetector detects the intensity of the light transmitted through the optical filter. Therefore, the light intensity is more accurately measured by calibrating the intensity according to the wavelength.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: November 17, 2009
    Assignee: Raybit Systems Inc.
    Inventors: Gap Youl Lyu, Kilhun Koo, Min Hee Kang, Ba Cao
  • Patent number: 7512166
    Abstract: The present invention relates to an optical power and extinction ratio controlling device and method. An optical signal output from a light source is detected and optical power and extinction ratio of the light source are controlled. In detail, a feedback signal is provided to the light source to automatically control the bias current based on a DC signal output by a photodetector detecting the optical signal. Therefore, the optical output of the light source is maintained. Also, an optical signal output by the photodetector is converted into a predetermined times DC signal, and a feedback signal is provided to the light source to automatically control the modulation current based on the DC signal. Therefore, the extinction ratio of the light source is maintained. As a result, the extinction ratio is automatically maintained to satisfy the change of condition and the characteristic of light source, thereby maintaining quality optical outputs.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: March 31, 2009
    Assignee: Raybit Systems
    Inventors: Gap Youl Lyu, Kilhun Koo, Min Hee Kang
  • Publication number: 20090033923
    Abstract: The present invention relates to a light wavelength and intensity measuring device. The device automatically measures a center wavelength of the light source and an intensity of the light corresponding to the center wavelength by using a main photodetector, at least one optical filter, and at least one sub photodetector when the light source is connected to the device. The main photodetector detects the intensity of the light applied by the light source, the optical filter transmits the light corresponding to a prediscriminated transmission wavelength, and the sub photodetector detects the intensity of the light transmitted through the optical filter. Therefore, the light intensity is more accurately measured by calibrating the intensity according to the wavelength.
    Type: Application
    Filed: June 7, 2006
    Publication date: February 5, 2009
    Inventors: Gap Youl Lyu, Kilhun Koo, Min Hee Kang, Ba Cao
  • Publication number: 20080128587
    Abstract: The present invention relates to an optical power and extinction ratio controlling device and method. An optical signal output from a light source is detected and optical power and extinction ratio of the light source are controlled. In detail, a feedback signal is provided to the light source to automatically control the bias current based on a DC signal output by a photodetector detecting the optical signal. Therefore, the optical output of the light source is maintained. Also, an optical signal output by the photodetector is converted into a predetermined times DC signal, and a feedback signal is provided to the light source to automatically control the modulation current based on the DC signal. Therefore, the extinction ratio of the light source is maintained. As a result, the extinction ratio is automatically maintained to satisfy the change of condition and the characteristic of light source, thereby maintaining quality optical outputs.
    Type: Application
    Filed: December 1, 2006
    Publication date: June 5, 2008
    Applicant: Raybit Systems Inc.
    Inventors: Gap Youl Lyu, Kilhun Koo, Min Hee Kang