Patents by Inventor Tatsuo Nagashima

Tatsuo Nagashima 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: 7336413
    Abstract: A nonlinear fiber having a third-order nonlinear coefficient of at least 30 W?1km?1, and its cladding containing Er or Tm at a portion within 3 ?m from the interface with its core. A wavelength conversion method of making a signal light having a wavelength ?S and an intensity IS and a pump light having a wavelength ?P which is shorter than 2?S and an intensity higher than IS enter a nonlinear fiber 1, and generating a converted light having a wavelength ?C of ?S?P/(2?S??P) and an intensity IC by four wave mixing, wherein Er or Tm is present in the cladding at a portion with a diameter in the nonlinear fiber 1 of at most the mode field diameter, and the converted light is generated by four wave mixing while Er or Tm is excited by an excitation light.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: February 26, 2008
    Assignee: Asahi Glass Company, Limited
    Inventors: Tomoharu Hasegawa, Naoki Sugimoto, Tatsuo Nagashima
  • Publication number: 20070081777
    Abstract: A nonlinear fiber having a third-order nonlinear coefficient of at least 30 W?1km?1, and its cladding containing Er or Tm at a portion within 3 ?m from the interface with its core. A wavelength conversion method of making a signal light having a wavelength ?S and an intensity IS and a pump light having a wavelength ?P which is shorter than 2?S and an intensity higher than IS enter a nonlinear fiber 1, and generating a converted light having a wavelength ?C of ?S?P/(2?S??P) and an intensity IC by four wave mixing, wherein Er or Tm is present in the cladding at a portion with a diameter in the nonlinear fiber 1 of at most the mode field diameter, and the converted light is generated by four wave mixing while Er or Tm is excited by an excitation light.
    Type: Application
    Filed: October 31, 2006
    Publication date: April 12, 2007
    Applicant: ASAHI GLASS COMPANY LIMITED
    Inventors: Tomoharu Hasegawa, Naoki Sugimoto, Tatsuo Nagashima
  • Publication number: 20060100084
    Abstract: A non-lead optical glass consisting essentially of, as represented by mol %, from 45 to 75% of Bi2O3, from 12 to 45% of B2O3, from 1 to 20% of Ga2O3, from 1 to 20% of In2O3, from 0 to 20% of ZnO, from 0 to 15% of BaO, from 0 to 15% of SiO2+Al2O3+GeO2, from 0 to 15% of MgO+CaO+SrO, from 0 to 10% of SnO2+TeO2+TiO2+ZrO2+Ta2O3+Y2O3+WO3 and from 0 to 5% of CeO2, wherein Ga2O3+In2O3+ZnO?5%. An optical fiber comprising the above non-lead optical glass as a core.
    Type: Application
    Filed: December 20, 2005
    Publication date: May 11, 2006
    Applicant: Asahi Glass Company, Limited
    Inventors: Tatsuo Nagashima, Naoki Sugimoto, Seiki Ohara, Tomoharu Hasegawa
  • Patent number: 6599852
    Abstract: An optical amplifying glass comprising a matrix glass and from 0.001 to 10% by mass percentage of Tm doped to the matrix glass, wherein the matrix glass contains from 15 to 80 mol % of Bi2O3 and further contains at least one component selected from the group consisting of SiO2, B2O3 and GeO2.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: July 29, 2003
    Assignee: Asahi Glass Company, Limited
    Inventors: Yuki Kondo, Setsuro Ito, Naoki Sugimoto, Tatsuo Nagashima, Setsuhisa Tanabe
  • Publication number: 20020041436
    Abstract: An optical amplifying glass comprising a matrix glass and from 0.001 to 10% by mass percentage of Tm doped to the matrix glass, wherein the matrix glass contains from 15 to 80 mol % of Bi2O3 and further contains at least one component selected from the group consisting of SiO2, B2O3 and GeO2.
    Type: Application
    Filed: August 8, 2001
    Publication date: April 11, 2002
    Applicant: Asahi Glass Company, Limited
    Inventors: Yuki Kondo, Setsuro Ito, Naoki Sugimoto, Tatsuo Nagashima, Setsuhisa Tanabe