Patents by Inventor Hirokazu Hayakawa

Hirokazu Hayakawa 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).

  • Publication number: 20240087916
    Abstract: A vacuum processing apparatus includes a decompressable process container; a supply port configured to supply, to the process container, an ionic liquid that absorbs an oxidizing gas; and a discharge port configured to discharge the ionic liquid supplied to the process container. A recess is provided at a joint portion between members constituting the process container. The supply port is configured to supply the ionic liquid to the recess, and the discharge port is configured to discharge the ionic liquid supplied to the recess.
    Type: Application
    Filed: November 1, 2023
    Publication date: March 14, 2024
    Inventors: Hirokazu UEDA, Yoji IIZUKA, Mitsuaki IWASHITA, Antonio ROTONDARO, Dipak ARYAL, Takeo NAKANO, Ryuichi ASAKO, Kenji SEKIGUCHI, Koji AKIYAMA, Naoki UMESHITA, Takashi HAYAKAWA
  • Patent number: 5973808
    Abstract: An optical fiber amplifier is free from optical oscillation, if operated for high output power level and can be manufactured at low cost. It comprises an input optical fiber 11 for receiving signal light, a first isolator 12 for blocking any return light of the optical signal entered into the input optical fiber 11, an erbium-doped optical fiber 13 for amplifying the entered optical signal, a pumping source 14, a wavelength division multiplexer 15 for coupling the signal light and the excited light from the pumping source 14, an optical signal output optical fiber 16 connected to the wavelength division multiplexer 15 to produce an amplified optical signal, a second isolator 17 arranged on the optical signal output optical fiber 16 and a excited light input optical fiber 19 for connecting the wavelength division multiplexer 15 and the pumping source 14 and the wavelength division multiplexer 15 has a dielectric multilayer filter 18 that reflects signal light and transmits excited light.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: October 26, 1999
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Tokushi Sekimura, Hirokazu Hayakawa
  • Patent number: 5301252
    Abstract: The present invention provides a mode field conversion fiber component formed by fusion-connecting connection end surfaces of two optical components having different mode fields. The mode fields of the two optical components are conformed to each other at the connection end surfaces, and are continuously varied near the connection end surfaces. The present invention also provides a method for manufacturing a mode field conversion fiber component, having the steps of butting connection end surfaces of two optical fibers having different mode fields, fusion-connecting the connection end surfaces of the two optical fibers, and heating a fusion-connecting portion of the connection end surfaces, diffusing core dopant, and conforming the mode fields of the two optical fibers.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: April 5, 1994
    Assignee: The Furukawa Electric Company, Ltd.
    Inventors: Hisaharu Yanagawa, Hirokazu Hayakawa
  • Patent number: 4958897
    Abstract: An optical component and a manufacturing method therefor are provided, in which an optical member is arranged across a spot-size enlarged portion of an optical fiber. The spot-size enlarged portion is formed either by heating and drawing an optical fiber to reduce its diameter or by diffusing core dopant of an optical fiber outwardly while heating the same. The optical component functions as an optical filter, an optical attenuator, a polarizer, a wavelength division multiplexer/demultiplexer or the like, depending on selection of the optical member.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: September 25, 1990
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Hisaharu Yanagawa, Toshihiro Ochiai, Hirokazu Hayakawa, Hidehisa Miyazawa
  • Patent number: 4900118
    Abstract: Opposed ones of optical fibers respectively secured in a plurality of guide grooves formed in first and second blocks, are jointed to each other through an optical film formed on at least one of their opposed inclined end faces in such a way that their optical axes are aligned with each other. Further, each of optical fibers similarly disposed on a third block is formed at its one end face with a total reflection film and is arranged in parallel to the optical fibers of the first and second blocks in such a way that an optical signal incident to the respective fibers of the first block is propagated through the splitting films and total reflection films along optical axes of the associated optical fibers of the third block.
    Type: Grant
    Filed: May 16, 1988
    Date of Patent: February 13, 1990
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Hisaharu Yanagawa, Hirokazu Hayakawa, Mikio Ogai, Toshihiro Ochiai, Hidehisa Miyazawa