Patents by Inventor Yukihiro Tsuchida

Yukihiro Tsuchida 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: 20180356589
    Abstract: An optical fiber that has an air layer in a clad portion and can suppress a degradation in a transmission characteristic caused by a support member present in the air layer is provided. The optical fiber includes a core (1), tubular layers (22 to 25) concentrically arranged around the core (1) via the air layer, and support members (3a to 3l) that are arranged to the air layer and connect the core (1) with the tubular layers (22 to 25), and in the optical fiber, in a cross-sectional view of a longitudinal direction of the optical fiber, a distance between support members (3a to 3l) in a circumferential direction of the optical fiber is wider than a double thickness of the air layer in which the support members (3a to 3l) are arranged.
    Type: Application
    Filed: August 17, 2018
    Publication date: December 13, 2018
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kazunori MUKASA, Yukihiro TSUCHIDA
  • Patent number: 9722388
    Abstract: A multi-core optical amplifying fiber device includes a plurality of multi-core optical amplifying fibers including a plurality of core portions doped with amplification medium and a cladding portion formed at outer peripheries of the plurality of core portions; and a connection portion connecting the core portions of the plurality of multi-core optical amplifying fibers to one another. The connection portion connects the core portions to restrain deviation, between every connected core portions, of amplification gain for a total length of the core portions connected one another.
    Type: Grant
    Filed: December 21, 2015
    Date of Patent: August 1, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masateru Tadakuma, Koichi Maeda, Yukihiro Tsuchida, Shigehiro Takasaka, Ryuichi Sugizaki
  • Patent number: 9692201
    Abstract: A bundle structure is obtained by arranging optical fibers having equal diameters in a close-packed arrangement around the outer circumference of a center optical fiber. The optical fibers are signal light optical fibers that transmit signal lights. The optical fiber is a pump light optical fiber that transmits pump light. The number of optical fibers is equal to the number of cores in the multi-core fiber. The bundle structure and the multi-core fiber are connected to one another by adhering or fusing. The cores and the cores are optically connected, and the core and the cladding are optically connected. When connecting, the mode field diameter of the cores and the cores are substantially equivalent. In addition, the outer diameter (diameter of circumscribed circle including optical fibers) of the bundle structure is set so as not to be greater than the outer diameter of the multi-core fiber.
    Type: Grant
    Filed: August 25, 2015
    Date of Patent: June 27, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kengo Watanabe, Tsunetoshi Saito, Yukihiro Tsuchida, Koichi Maeda, Katsunori Imamura
  • Patent number: 9423559
    Abstract: A multi-core amplification optical fiber includes: a plurality of core portions doped with a rare-earth element; an inner cladding portion positioned at a periphery of the plurality of core portions, having a refractive index lower than a refractive index of the plurality of core portions, in which a first hole is formed; and an outer cladding layer positioned at a periphery of the inner cladding portion, having a refractive index lower than the refractive index of the inner cladding portion.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: August 23, 2016
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro Tsuchida, Yu Mimura
  • Publication number: 20160118762
    Abstract: A multi-core optical amplifying fiber device includes a plurality of multi-core optical amplifying fibers including a plurality of core portions doped with amplification medium and a cladding portion formed at outer peripheries of the plurality of core portions; and a connection portion connecting the core portions of the plurality of multi-core optical amplifying fibers to one another. The connection portion connects the core portions to restrain deviation, between every connected core portions, of amplification gain for a total length of the core portions connected one another.
    Type: Application
    Filed: December 21, 2015
    Publication date: April 28, 2016
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masateru TADAKUMA, Koichi MAEDA, Yukihiro TSUCHIDA, Shigehiro TAKASAKA, Ryuichi SUGIZAKI
  • Publication number: 20160028206
    Abstract: A bundle structure is obtained by arranging optical fibers having equal diameters in a close-packed arrangement around the outer circumference of a center optical fiber. The optical fibers are signal light optical fibers that transmit signal lights. The optical fiber is a pump light optical fiber that transmits pump light. The number of optical fibers is equal to the number of cores in the multi-core fiber. The bundle structure and the multi-core fiber are connected to one another by adhering or fusing. The cores and the cores are optically connected, and the core and the cladding are optically connected. When connecting, the mode field diameter of the cores and the cores are substantially equivalent. In addition, the outer diameter (diameter of circumscribed circle including optical fibers) of the bundle structure is set so as not to be greater than the outer diameter of the multi-core fiber.
    Type: Application
    Filed: August 25, 2015
    Publication date: January 28, 2016
    Inventors: Kengo WATANABE, Tsunetoshi SAITO, Yukihiro TSUCHIDA, Koichi MAEDA, Katsunori IMAMURA
  • Publication number: 20160020573
    Abstract: An optical-fiber-bundle structure is connected to one end of a multi-core fiber. The multi-core fiber has a tapered section formed therein. The outside diameter of the multi-core fiber and the core pitch thereof decrease in the tapered section. It is possible for the multi-core fiber to have an increasing core pitch on the connection-side thereof which connects to the optical-fiber-bundle structure; hence, it is possible to use an easy-to-use large-diameter optical fiber as the optical fiber to be provided in the optical-fiber-bundle structure. When connecting another multi-core fiber to the other end of the multi-core fiber, it is possible to match the outer diameters thereof; hence, when fusion splicing to one another, it is unlikely for a positional shift of the cores to occur.
    Type: Application
    Filed: August 25, 2015
    Publication date: January 21, 2016
    Inventors: Kengo WATANABE, Tsunetoshi SAITO, Yukihiro TSUCHIDA, Koichi MAEDA, Katsunori IMAMURA
  • Patent number: 9225141
    Abstract: A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 ?m to 5 ?m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 ?m and at equal to or smaller than 60 ?m so that a light-crosstalk between the adjacent core portions is equal to or lower than ?30 dB.
    Type: Grant
    Filed: April 4, 2014
    Date of Patent: December 29, 2015
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro Tsuchida, Koichi Maeda, Yu Mimura, Hiroshi Matsuura, Kengo Watanabe, Tsunetoshi Saito, Ryo Miyabe, Shigeto Matsumoto, Keiichi Aiso, Ryuichi Sugizaki
  • Publication number: 20150316714
    Abstract: A multi-core amplification optical fiber includes: a plurality of core portions doped with a rare-earth element; an inner cladding portion positioned at a periphery of the plurality of core portions, having a refractive index lower than a refractive index of the plurality of core portions, in which a first hole is formed; and an outer cladding layer positioned at a periphery of the inner cladding portion, having a refractive index lower than the refractive index of the inner cladding portion.
    Type: Application
    Filed: December 13, 2013
    Publication date: November 5, 2015
    Applicant: Furukawa Electric Co., Ltd.
    Inventors: Yukihiro TSUCHIDA, Yu MIMURA
  • Publication number: 20140240819
    Abstract: A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 ?m to 5 ?m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 ?m and at equal to or smaller than 60 ?m so that a light-crosstalk between the adjacent core portions is equal to or lower than ?30 dB.
    Type: Application
    Filed: April 4, 2014
    Publication date: August 28, 2014
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro TSUCHIDA, Koichi Maeda, Yu Mimura, Hiroshi Matsuura, Kengo Watanabe, Tsunetoshi Saito, Ryo Miyabe, Shigeto Matsumoto, Keiichi Aiso, Ryuichi Sugizaki
  • Patent number: 8787720
    Abstract: An optical fiber includes a core portion that confines light therein and guides the light therethrough and a cladding portion that is formed around an outer circumference of the core portion. The cladding portion contains a hole which is formed at a position a distance away from the core portion such that the hole does not substantially affect an effective core area or a chromatic dispersion characteristic of the optical fiber. The hole decreases a microbending loss of the optical fiber.
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: July 22, 2014
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Kazunori Mukasa, Yukihiro Tsuchida
  • Patent number: 8437594
    Abstract: A holey fiber includes a core portion located at a center of the holey fiber, and a cladding portion located around the core portion, the cladding portion having holes formed in layers around the core portion. The holes are arranged so as to form a triangular lattice while d/? is within a range of 0.33 to 0.43, ? is within a range of 10.5 micrometers to 15 micrometers when a hole diameter is d in micrometer and a lattice constant of the triangular lattice is ? in micrometer, and in a wavelength of 1550 nanometer, an effective core-area is equal to or greater than 130 ?m2, a bending loss in a case of bending the holey fiber at a bend diameter of 20 millimeters is equal to or less than 200 dB/m, and the holey fiber demonstrates a single-mode operation.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: May 7, 2013
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Yukihiro Tsuchida, Kazunori Mukasa
  • Patent number: 8315494
    Abstract: An optical fiber includes a center core portion; an inner core layer formed around an outer circumference of the center core portion, a refractive index of which is less than that of the center core portion; an outer core layer formed around an outer circumference of the inner core layer, a refractive index of which is less than that of the inner core layer; and a cladding portion formed around an outer circumference of the outer core layer. A refractive index of the cladding portion is substantially equal to that of the inner core layer. At a wavelength of 1550 nm, an effective core area is equal to or larger than 130 ?m2 and a bending loss is equal to or less than 100 dB/m when the optical fiber is bent with a diameter of 20 mm. A cable cut-off wavelength is equal to or less than 1530 nm.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: November 20, 2012
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Yukihiro Tsuchida, Kazunori Mukasa
  • Publication number: 20120177333
    Abstract: An optical fiber includes a center core portion; an inner core layer formed around an outer circumference of the center core portion, a refractive index of which is less than that of the center core portion; an outer core layer formed around an outer circumference of the inner core layer, a refractive index of which is less than that of the inner core layer; and a cladding portion formed around an outer circumference of the outer core layer. A refractive index of the cladding portion is substantially equal to that of the inner core layer. At a wavelength of 1550 nm, an effective core area is equal to or larger than 130 ?m2 and a bending loss is equal to or less than 100 dB/m when the optical fiber is bent with a diameter of 20 mm. A cable cut-off wavelength is equal to or less than 1530 nm.
    Type: Application
    Filed: March 16, 2012
    Publication date: July 12, 2012
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro TSUCHIDA, Kazunori MUKASA
  • Publication number: 20120141078
    Abstract: An optical fiber includes a core portion that confines light therein and guides the light therethrough and a cladding portion that is formed around an outer circumference of the core portion. The cladding portion contains a hole which is formed at a position a distance away from the core portion such that the hole does not substantially affect an effective core area or a chromatic dispersion characteristic of the optical fiber. The hole decreases a microbending loss of the optical fiber.
    Type: Application
    Filed: February 13, 2012
    Publication date: June 7, 2012
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kazunori MUKASA, Yukihiro TSUCHIDA
  • Publication number: 20120134636
    Abstract: A holey fiber includes a core portion located at a center of the holey fiber, and a cladding portion located around the core portion, the cladding portion having holes formed in layers around the core portion. The holes are arranged so as to form a triangular lattice while d/? is within a range of 0.33 to 0.43, ? is within a range of 10.5 micrometers to 15 micrometers when a hole diameter is d in micrometer and a lattice constant of the triangular lattice is ? in micrometer, and in a wavelength of 1550 nanometer, an effective core-area is equal to or greater than 130 ?m2, a bending loss in a case of bending the holey fiber at a bend diameter of 20 millimeters is equal to or less than 200 dB/m, and the holey fiber demonstrates a single-mode operation.
    Type: Application
    Filed: February 6, 2012
    Publication date: May 31, 2012
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro Tsuchida, Kazunori Mukasa