Patents by Inventor Azusa URUSHIBARA

Azusa URUSHIBARA 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 fiber and optical transmission system
    Patent number: 11156767
    Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.
    Type: Grant
    Filed: July 31, 2018
    Date of Patent: October 26, 2021
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Azusa Urushibara, Taiji Sakamoto, Masaki Wada, Takashi Yamamoto, Kazuhide Nakajima, Takayoshi Mori
  • Optical fiber and optical transmission system
    Patent number: 10790905
    Abstract: The optical fiber according to the present disclosure is an optical fiber having a pure silica core which is a step index core through which an LPm1 mode with an effective area of 250 ?m2 or more is propagated by setting a relative refractive index difference to 0.60% or less, considering an effective cutoff condition, and only 2 or more modes or the LPm1 mode are propagated, with the optical fiber as the transmission line.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: September 29, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takayoshi Mori, Taiji Sakamoto, Takashi Yamamoto, Kazuhide Nakajima, Masaki Wada, Azusa Urushibara
  • OPTICAL FIBER AND OPTICAL TRANSMISSION SYSTEM
    Publication number: 20200225407
    Abstract: The optical fiber of the present invention includes a core, and a cladding that is provided on an outer periphery of the core and has a refractive index lower than a refractive index of the core region. In the optical fiber of the present invention, a V value representing a normalized frequency of an LP02 mode is greater than or equal to 4.8 and less than or equal to 6.4.
    Type: Application
    Filed: July 31, 2018
    Publication date: July 16, 2020
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Azusa URUSHIBARA, Taiji SAKAMOTO, Masaki WADA, Takashi YAMAMOTO, Kazuhide NAKAJIMA, Takayoshi MORI
  • Optical transmission system
    Patent number: 10705291
    Abstract: An optical transmission system according to the present disclosure is a mode multiplexed optical transmission system using a multi-mode optical fiber in which a plurality of propagation modes propagate as a transmission line, the optical transmission system including an optical fiber transmission line (83) that includes an optical fiber with two or more propagation modes; and a plurality of mode converters (91) that are configured to generate mode coupling between at least one pair of the propagation modes, in which a variation in an installation interval of the plurality of mode converters (91) is equal to or less than a threshold value determined by the transmission line length (Lt) of the optical fiber transmission line (83).
    Type: Grant
    Filed: August 25, 2017
    Date of Patent: July 7, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Azusa Urushibara, Takayoshi Mori, Taiji Sakamoto, Masaki Wada, Takashi Yamamoto, Kazuhide Nakajima
  • OPTICAL FIBER AND OPTICAL TRANSMISSION SYSTEM
    Publication number: 20190386748
    Abstract: The optical fiber according to the present disclosure is an optical fiber having a pure silica core which is a step index core through which an LPm1 mode with an effective area of 250 ?m2 or more is propagated by setting a relative refractive index difference to 0.60% or less, considering an effective cutoff condition, and only 2 or more modes or the LPm1 mode are propagated, with the optical fiber as the transmission line.
    Type: Application
    Filed: July 4, 2017
    Publication date: December 19, 2019
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Takayoshi MORI, Taiji SAKAMOTO, Takashi YAMAMOTO, Kazuhide NAKAJIMA, Masaki WADA, Azusa URUSHIBARA
  • OPTICAL TRANSMISSION SYSTEM
    Publication number: 20190187365
    Abstract: An optical transmission system according to the present disclosure is a mode multiplexed optical transmission system using a multi-mode optical fiber in which a plurality of propagation modes propagate as a transmission line, the optical transmission system including an optical fiber transmission line (83) that includes an optical fiber with two or more propagation modes; and a plurality of mode converters (91) that are configured to generate mode coupling between at least one pair of the propagation modes, in which a variation in an installation interval of the plurality of mode converters (91) is equal to or less than a threshold value determined by the transmission line length (Lt) of the optical fiber transmission line (83).
    Type: Application
    Filed: August 25, 2017
    Publication date: June 20, 2019
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Azusa URUSHIBARA, Takayoshi MORI, Taiji SAKAMOTO, Masaki WADA, Takashi YAMAMOTO, Kazuhide NAKAJIMA