Patents by Inventor Katsutoshi KODA

Katsutoshi KODA 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).

  • Optical transmitter, optical receiver, and optical transmission system
    Patent number: 10951344
    Abstract: An optical transmitter generates two modulated optical signals by modulating two optical carriers respectively with two binary bit sequences by on-off keying and generates an orthogonal polarization multiplexed optical signal from the two modulated optical signals. The two optical carriers respectively have peak frequency components spaced apart from each other by a predetermined frequency difference and located such that a central frequency of a WDM channel of a WDM grid falls between the peak frequency components. An optical receiver separates the orthogonal polarization multiplexed optical signal into two signals in which components of the two modulated optical signals are combined with different combination ratios, by means of a 1-input, 2-output asymmetric filter whose two optical transmittances intersect at the WDM grid and each have a free spectral range equal to or twice the channel spacing of the WDM grid, and restores the two modulated optical signals from the separated two signals using a DSP.
    Type: Grant
    Filed: June 21, 2018
    Date of Patent: March 16, 2021
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Toshiya Matsuda, Toru Homemoto, Kana Masumoto, Masaru Katayama, Katsutoshi Koda
  • OPTICAL TRANSMITTER, OPTICAL RECEIVER, AND OPTICAL TRANSMISSION SYSTEM
    Publication number: 20200127757
    Abstract: An optical transmitter generates two modulated optical signals by modulating two optical carriers respectively with two binary bit sequences by on-off keying and generates an orthogonal polarization multiplexed optical signal from the two modulated optical signals. The two optical carriers respectively have peak frequency components spaced apart from each other by a predetermined frequency difference and located such that a central frequency of a WDM channel of a WDM grid falls between the peak frequency components. An optical receiver separates the orthogonal polarization multiplexed optical signal into two signals in which components of the two modulated optical signals are combined with different combination ratios, by means of a 1-input, 2-output asymmetric filter whose two optical transmittances intersect at the WDM grid and each have a free spectral range equal to or twice the channel spacing of the WDM grid, and restores the two modulated optical signals from the separated two signals using a DSP.
    Type: Application
    Filed: June 21, 2018
    Publication date: April 23, 2020
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Toshiya MATSUDA, Toru HOMEMOTO, Kana MASUMOTO, Masaru KATAYAMA, Katsutoshi KODA