Patents by Inventor Ryuichi Sugizaki

Ryuichi Sugizaki 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: 20220003921
    Abstract: A multicore fiber includes: n pieces of first core regions in a circular shape with a radius r1 that are arranged about points P11 to P1n, and that has a first core portion and a first cladding portion; a second core region in a circular shape with a radius R1 that is arranged about the point a1, and that has a second core portion and a second cladding portion; and a cladding region that is formed on an outer circumferences of the first core region and the second core region. Further, abutting surfaces that are flat surfaces abutting on each other are formed in portions on the outer circumferences of the first core region and the second core region.
    Type: Application
    Filed: September 20, 2021
    Publication date: January 6, 2022
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masanori TAKAHASHI, Koichi MAEDA, Shinichi ARAI, Ryuichi SUGIZAKI, Masayoshi TSUKAMOTO
  • Publication number: 20220003924
    Abstract: An optical fiber bundle structure includes: plural optical fiber core wires; a crossing preventing member; and a grasping member. Further, the crossing preventing member has slits and the widths of the slits positioned at the respective sides are each equal to or larger than a difference between: a length of one side of a polygon circumscribing the plural optical fiber core wires at a hindmost end portion of the slits at the trailing end; and a length of one side of a polygon circumscribing the plural optical fiber core wires at the leading end.
    Type: Application
    Filed: September 20, 2021
    Publication date: January 6, 2022
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kohei KAWASAKI, Ryuichi SUGIZAKI, Masayoshi TSUKAMOTO, Masanori TAKAHASHI, Shigehiro TAKASAKA, Koichi MAEDA
  • Publication number: 20210116265
    Abstract: A cable comprising: a plurality of optical fiber cores; and one or more optical fiber core wires including one or more of the optical fiber cores. Further, at least one of the optical fiber core wire is fixed at a plurality of positions in a longitudinal direction of the cable so as to achieve substantially no displacement in a cable radial direction, at least a pair of the optical fiber core wires are fixed in a plane perpendicular to the longitudinal direction of the cable so as to achieve substantially no displacement relative to each other, and sensing of a strain profile in the longitudinal direction of at least the pair of the optical fiber core wires leads to achievement of sensing of a shape of the cable in the longitudinal direction.
    Type: Application
    Filed: December 29, 2020
    Publication date: April 22, 2021
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Masateru TADAKUMA, Shigehiro TAKASAKA, Ryuichi SUGIZAKI
  • Patent number: 9891378
    Abstract: A multicore fiber includes a plurality of unit multicore fibers each including: a plurality of core portions; and a clad portion which is formed in an outer circumference of the core portions and has a refractive index lower than a maximum refractive index of the core portions. The plurality of the core portions have substantially same refractive index profile and different group delays at same wavelength in same propagation mode. The core portions of the multicore fiber are configured so that the core portions of the plurality of the unit multicore fibers are connected in cascade, a maximum value of differential group delays between the core portions of the multicore fiber is smaller than a reduced value of a maximum value of differential group delays between the core portions of each unit multicore fiber as a value in terms of a length of the multicore fiber.
    Type: Grant
    Filed: February 23, 2017
    Date of Patent: February 13, 2018
    Assignees: FURUKAWA ELECTRIC CO., LTD., NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsunori Imamura, Tomohiro Gonda, Ryuichi Sugizaki, Taiji Sakamoto, Takayoshi Mori, Masaki Wada, Takashi Yamamoto, Fumihiko Yamamoto
  • 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: 9695079
    Abstract: A production method of an optical fiber preform includes first preparing a first preform having a plurality of glass preforms and a first cladding portion disposed between the plurality of glass preforms, and first arranging a second cladding portion to surround the first preform. At the first arranging, a material gas and a combustion gas are ejected from a burner to produce glass particles. The first preform and the burner are moved relative to each other in a longitudinal direction of the first preform. The glass particles are deposited on the first preform.
    Type: Grant
    Filed: October 22, 2015
    Date of Patent: July 4, 2017
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tomohiro Gonda, Katsunori Imamura, Ryo Miyabe, Ryuichi Sugizaki
  • Publication number: 20170160466
    Abstract: A multicore fiber includes a plurality of unit multicore fibers each including: a plurality of core portions; and a clad portion which is formed in an outer circumference of the core portions and has a refractive index lower than a maximum refractive index of the core portions. The plurality of the core portions have substantially same refractive index profile and different group delays at same wavelength in same propagation mode. The core portions of the multicore fiber are configured so that the core portions of the plurality of the unit multicore fibers are connected in cascade, a maximum value of differential group delays between the core portions of the multicore fiber is smaller than a reduced value of a maximum value of differential group delays between the core portions of each unit multicore fiber as a value in terms of a length of the multicore fiber.
    Type: Application
    Filed: February 23, 2017
    Publication date: June 8, 2017
    Applicants: FURUKAWA ELECTRIC CO., LTD., NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsunori IMAMURA, Tomohiro GONDA, Ryuichi SUGIZAKI, Taiji SAKAMOTO, Takayoshi MORI, Masaki WADA, Takashi YAMAMOTO, Fumihiko YAMAMOTO
  • Publication number: 20160347645
    Abstract: A production method of an optical fiber preform includes: preparing a plurality of bar-shaped first preforms and a plurality of second preforms including through holes having substantially same shape with a shape of outer periphery of a cross section of the first preform, the cross section being orthogonal to a major axis of the first preform; and an assembly step of: matching the through holes of the second preforms to make communication holes; and inserting, through each of the communication holes, at least two of the first preforms arranged side by side in a direction of the major axis such that the second preforms and the first preforms are fitting each other. In at least one position in the direction of the major axis of the communication holes, a position where the second preforms contact with each other differs from a position where the first preforms contact with each other.
    Type: Application
    Filed: August 9, 2016
    Publication date: December 1, 2016
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tomohiro GONDA, Ryo MIYABE, Katsunori IMAMURA, Tsunetoshi SAITO, Ryuichi SUGIZAKI
  • Publication number: 20160216440
    Abstract: An optical fiber includes a core portion, and a cladding portion being formed at an outer periphery of the core portion and having a refractive index lower than a maximum refractive index of the core portion. The core portion has ?-shaped refractive index profile in which a value of ? is equal to or greater than 3 and equal to or smaller than 10, and at least a diameter of the core portion and a relative refractive-index difference of the core portion relative to the cladding portion are set so that light can be propagated with equal to or greater than 6 propagation modes at a wavelength of light inputted.
    Type: Application
    Filed: April 1, 2016
    Publication date: July 28, 2016
    Applicant: Furukawa Electric Co., Ltd.
    Inventors: Katsunori IMAMURA, Ryuichi SUGIZAKI, Takehiro TSURITANI, Koji IGARASHI
  • 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: 20160075590
    Abstract: A production method of an optical fiber preform includes first preparing a first preform having a plurality of glass preforms and a first cladding portion disposed between the plurality of glass preforms, and first arranging a second cladding portion to surround the first preform. At the first arranging, a material gas and a combustion gas are ejected from a burner to produce glass particles. The first preform and the burner are moved relative to each other in a longitudinal direction of the first preform. The glass particles are deposited on the first preform.
    Type: Application
    Filed: October 22, 2015
    Publication date: March 17, 2016
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Tomohiro GONDA, Katsunori IMAMURA, Ryo MIYABE, Ryuichi SUGIZAKI
  • 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
  • Patent number: 9075185
    Abstract: A hole-assisted optical fiber includes a core portion and a cladding portion that includes an inner cladding layer, an outer cladding layer, and holes formed around the core portion. A diameter of the core portion is 3 ?m to 9.8 ?m, a relative refractive index difference of the core portion relative to the outer cladding layer is 0.11% to 0.45%, an outside diameter of the inner cladding layer is 53 ?m or less, a relative refractive index difference of the inner cladding layer relative to the outer cladding layer is a negative value, ?0.30% or more, a diameter of each hole is 2.4 ?m to 4.0 ?m, a hole occupancy rate is 17% to 48%, a bending loss at a wavelength of 1625 nm when bent at a radius of 5 mm is 1 dB/turn or less, and a cut-off wavelength is 1550 nm or less.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: July 7, 2015
    Assignees: FURUKAWA ELECTRIC CO., LTD., NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Naomi Kumano, Iwao Shimotakahara, Ryuichi Sugizaki, Takeshi Yagi, Tomoya Shimizu, Takashi Matsui, Yukihiro Goto, Toshio Kurashima, Kazuhide Nakajima
  • Patent number: 8977096
    Abstract: An optical fiber suitable for high-capacity transmission having a large effective core area, a low bending loss, and capable of single mode operation at 1550 nm is provided. The optical fiber 10 has an effective core area ?175 ?m2 at 1550 nm, a bending loss ?10 dB/m at a bending diameter of 20 mm at 1550 nm, and a cut-off wavelength ?c?1550 nm. The optical fiber has a first core 11 at the center, which has a refractive index higher than that of the cladding 13; and a second core 12 around the first core 11, which has a refractive index lower than that of the cladding 13; a primary medium portion; and secondary medium portions, which have a refractive index lower than that of the primary medium portion and the secondary medium portions have a plurality of first secondary medium portions 15 around the first core 11 and a plurality of second secondary medium portions 16 around the first core 11 and outside of the first secondary medium portions 15.
    Type: Grant
    Filed: April 27, 2010
    Date of Patent: March 10, 2015
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Iwao Shimotakahara, Ryuichi Sugizaki, Takeshi Yagi
  • 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
  • Publication number: 20120195560
    Abstract: An optical fiber module includes a polarization-maintaining highly-nonlinear optical fiber and a housing. The polarization-maintaining highly-nonlinear optical fiber includes a core, a cladding surrounding the core and having two stress applying portions formed to sandwich the core and extend along the core, and a coating covering the cladding. The housing houses the polarization-maintaining highly-nonlinear optical fiber which is wound in a ring coil shape. The polarization-maintaining highly-nonlinear optical fiber has a bending loss of 0.01 dB/turn or less at a wavelength of 1550 nm when bent to form a diameter of 20 mm, a nonlinear coefficient ? of 10 W1 km?1 or larger at the wavelength of 1550 nm, a cutoff wavelength ?c of 1530 nm or shorter, and a zero-dispersion wavelength of not shorter than 1400 nm and not longer than 1650 nm.
    Type: Application
    Filed: April 12, 2012
    Publication date: August 2, 2012
    Applicant: Furukawa Electric Co., Ltd.
    Inventors: Masanori TAKAHASHI, Tomohiro Gonda, Ryuichi Sugizaki
  • Patent number: 8181487
    Abstract: An optical fiber preform manufacturing method includes: supporting a drilling jig in a radial direction of a preform that is cylinder-shaped; moving the drilling jig in a longitudinal direction of the preform; and forming a plurality of slits each extending in the longitudinal direction and each directed from an outer side of the preform toward a center the preform, and a plurality of holes each extending in the longitudinal direction and each connecting with an end of one of the plurality of slits in a depth direction of the one of the plurality of slits.
    Type: Grant
    Filed: September 3, 2010
    Date of Patent: May 22, 2012
    Assignees: Furukawa Electric Co., Ltd., Nippon Telegraph and Telephone Corporation
    Inventors: Ryuichi Sugizaki, Naomi Kumano, Iwao Shimotakahara, Harumi Inaba, Takeshi Yagi, Tomoya Shimizu, Toshio Kurashima, Kazuhide Nakajima
  • Patent number: 7925132
    Abstract: A core includes a center core region, a core layer that is formed around the center core region and that has a refractive index lower than that of the center core region, and at least one buffer core layer that is formed between the center core region and the core layer and that has a refractive index lower than that of the center core region and higher than that of the core layer. A cladding is formed around the core layer and that has a refractive index lower than that of the center core region and higher than that of the core layer. An effective core area at a wavelength of 1550 nm is equal to or smaller than 18 ?m2.
    Type: Grant
    Filed: June 19, 2009
    Date of Patent: April 12, 2011
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Yuki Taniguchi, Jiro Hiroishi, Masanori Takahashi, Ryuichi Sugizaki
  • Patent number: 7878712
    Abstract: An optical fiber has a refractive index profile approximated by n(r)=n1[1-2(?1/100)(r/a)^?]1/2 when 0<r?a, and n(r)=n1[1-2(?1/100)]1/2 when a<r, where n1 is refractive index at the center of a core, ?1 is relative refractive index difference between the center of the core and a cladding, a is radius of the core, ? is refractive index profile parameter, and ^ represents an exponential. ? is 1.95 to 2.15. The relative refractive index difference is 1.5% or larger. A diameter of the core is 20 ?m to 45 ?m. A diameter of the cladding is 70 ?m to 90 ?m. A bending loss at 850 nm when bending the optical fiber with a curvature radius of 5 mm is 0.1 dB/turn or lower.
    Type: Grant
    Filed: October 24, 2008
    Date of Patent: February 1, 2011
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Iwao Shimotakahara, Harumi Inaba, Ryuichi Sugizaki
  • Publication number: 20100326139
    Abstract: An optical fiber preform manufacturing method includes: supporting a drilling jig in a radial direction of a preform that is cylinder-shaped; moving the drilling jig in a longitudinal direction of the preform; and forming a plurality of slits each extending in the longitudinal direction and each directed from an outer side of the preform toward a center the preform, and a plurality of holes each extending in the longitudinal direction and each connecting with an end of one of the plurality of slits in a depth direction of the one of the plurality of slits.
    Type: Application
    Filed: September 3, 2010
    Publication date: December 30, 2010
    Applicants: FURUKAWA ELECTRIC CO., LTD., NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Ryuichi SUGIZAKI, Naomi Kumano, Iwao Shimotakahara, Harumi Inaba, Takeshi Yagi, Tomoya Shimizu, Toshio Kurashima, Kazuhide Nakajima