Patents by Inventor Kohzo Hakuta

Kohzo Hakuta 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: 8385696
    Abstract: To provide an optical nanofiber resonator having an optical waveguide whose diameter is equal to or smaller than the wavelength of a propagation light, a light emitter disposed at a predetermined position of the optical waveguide, and a first reflector and a second reflector formed in the optical waveguide with the light emitter interposed therebetween, wherein at least one of the first reflector and the second reflector transmits a part of the propagation light. With such a configuration, the channeling efficiency of the light emitted from the light emitter and the propagation mode of the optical waveguide is dramatically improved.
    Type: Grant
    Filed: November 12, 2010
    Date of Patent: February 26, 2013
    Assignee: The University of Electro-Communications
    Inventors: Kohzo Hakuta, Kien Le Pham
  • Publication number: 20120121221
    Abstract: To provide an optical nanofiber resonator having an optical waveguide whose diameter is equal to or smaller than the wavelength of a propagation light, a light emitter disposed at a predetermined position of the optical waveguide, and a first reflector and a second reflector formed in the optical waveguide with the light emitter interposed therebetween, wherein at least one of the first reflector and the second reflector transmits a part of the propagation light. With such a configuration, the channeling efficiency of the light emitted from the light emitter and the propagation mode of the optical waveguide is dramatically improved.
    Type: Application
    Filed: November 12, 2010
    Publication date: May 17, 2012
    Applicant: The University of Electro-Communications
    Inventors: Kohzo HAKUTA, Kien Le Pham
  • Patent number: 5149659
    Abstract: The concentration of molecular fluorine in a mixed gas such as an excimer laser gas can be determined easily, quickly and accurately by passing the mixed gas through a column packed with an alkali metal or alkaline earth metal compound which has no halogen atom and reacts with fluorine to form a solid fluoride together with molecular oxygen and/or carbon dioxide and measuring the concentration of oxygen or carbon dioxide in the fluorine-free gas flowed out of the packed column. If the mixed gas initially contains molecular oxygen or carbon dioxide, its concentration is measured separately after fixing fluorine in another column packed with an element which forms a fluoride. This analyzing method can be used in a feedback control system for controlling the concentration of fluorine in an excimer laser gas during operation of the laser to thereby stabilize the laser output power.
    Type: Grant
    Filed: March 5, 1991
    Date of Patent: September 22, 1992
    Assignee: Central Glass Company, Limited
    Inventors: Kohzo Hakuta, Minoru Aramaki, Takashi Suen. A, Mitsuo Kodama, Hisaji Nakano, Shinsuke Nakagawa
  • Patent number: 5017499
    Abstract: The concentration of molecular fluorine in a mixed gas such as an excimer laser gas can be determined easily, quickly and accurately by passing the mixed gas through a column packed with an alakli metal or alkaline earth metal compound which has no halogen atom and reacts with fluorine to form a solid fluoride together with molecular oxygen and/or carbon dioxide and measuring the concentration of oxygen or carbon dioxide in the fluorine-free gas flowed out of the packed column. If the mixed gas initially contains molecular oxygen or carbon dioxide, its concentration is measured separately after fixing fluorine in another column packed with an element which forms a fluoride. This analyzing method can be used in a feedback control system for controlling the concentration of fluorine in an excimer laser gas during operation of the laser to thereby stabilize the laser output power.
    Type: Grant
    Filed: March 31, 1989
    Date of Patent: May 21, 1991
    Assignee: Central Glass Company, Limited
    Inventors: Kohzo Hakuta, Minoru Aramaki, Takashi Suenaga, Mitsuo Kodama, Hisaji Nakano, Shinsuke Nakagawa
  • Patent number: 4740982
    Abstract: A laser gas used in a rare gas halide excimer laser is efficiently refined with little loss of the essential rare gas such as Kr, Ar or Xe by contact of the laser gas with a solid alkaline compound, e.g. Ca(OH).sub.2, for conversion of acidic impurities and also the halogen source gas such as F.sub.2 or HCl into solid metal halides and contact of the remaining gas with zeolite which is adsorbent of the remaining impurities. When the halogen source gas comprises a highly oxidizing fluorine matter the laser gas is first brought into contact with a reactive metal, e.g. Si or Fe, to convert the oxidizing fluorine matter into metal fluorides to thereby prevent formation of O.sub.2, which is obstructive to the laser operation, by reaction of the oxidizing matter with the alkaline compound.
    Type: Grant
    Filed: September 22, 1986
    Date of Patent: April 26, 1988
    Assignee: Central Glass Company, Limited
    Inventors: Kohzo Hakuta, Minoru Aramaki, Takashi Suenaga