Patents by Inventor Yu Mimura

Yu Mimura 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: 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
  • Patent number: 9270076
    Abstract: An optical amplifier includes an optical gain fiber into which signal light and pump light are input and at least one relative phase shifter is inserted. Preferably, the relative phase shifter is inserted so that the relative phase in the lengthwise direction of the optical gain fiber falls within a predetermined range containing 0.5?. Preferably, the optical gain fiber is a highly non-linear optical fiber having a non-linearity constant of at least 10/W/km. Preferably, the dispersion of the optical gain fiber is within the range from ?1 ps/nm/km to 1 ps/nm/km in an amplification band. Preferably, the absolute value of the dispersion slope of the optical gain fiber at a zero dispersion wavelength is no greater than 0.05 ps/nm2/km.
    Type: Grant
    Filed: September 4, 2013
    Date of Patent: February 23, 2016
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Shigehiro Takasaka, Yu Mimura
  • 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
  • Patent number: 9140850
    Abstract: An optical coupling structure optically coupling a plurality of core portions and a plurality of core portions includes a plurality of first core portions outputting a plurality of lights, a first lens focusing or collimating the plurality of lights outputted from the plurality of first core portions, a second lens focusing the plurality of lights focused or collimated by the first lens, a plurality of second core portions, the plurality of lights focused by the second lens being inputted into the second core portions respectively, and an optical functional component disposed between the first lens and the second lens, the plurality of lights being inputted into the optical functional component. At least one of the first lens and the second lens is configured by a lens or a lens group focusing or collimating the plurality of lights collectively.
    Type: Grant
    Filed: December 16, 2013
    Date of Patent: September 22, 2015
    Assignees: FURUKAWA ELECTRIC CO., LTD., TOHOKU GAKUIN
    Inventors: Yu Mimura, Hiroshi Matsuura
  • Publication number: 20150168642
    Abstract: An optical coupling structure optically coupling a plurality of core portions and a plurality of core portions includes a plurality of first core portions outputting a plurality of lights, a first lens focusing or collimating the plurality of lights outputted from the plurality of first core portions, a second lens focusing the plurality of lights focused or collimated by the first lens, a plurality of second core portions, the plurality of lights focused by the second lens being inputted into the second core portions respectively, and an optical functional component disposed between the first lens and the second lens, the plurality of lights being inputted into the optical functional component. At least one of the first lens and the second lens is configured by a lens or a lens group focusing or collimating the plurality of lights collectively.
    Type: Application
    Filed: December 16, 2013
    Publication date: June 18, 2015
    Applicants: TOHOKU GAKUIN, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yu MIMURA, Hiroshi Matsuura
  • 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: 20140043674
    Abstract: An optical amplifier includes an optical gain fiber into which signal light and pump light are input and at least one relative phase shifter is inserted. Preferably, the relative phase shifter is inserted so that the relative phase in the lengthwise direction of the optical gain fiber falls within a predetermined range containing 0.5 ?. Preferably, the optical gain fiber is a highly non-linear optical fiber having a non-linearity constant of at least 10/W/km. Preferably, the dispersion of the optical gain fiber is within the range from ?1 ps/nm/km to 1 ps/nm/km in an amplification band. Preferably, the absolute value of the dispersion slope of the optical gain fiber at a zero dispersion wavelength is no greater than 0.05 ps/nm2/km.
    Type: Application
    Filed: September 4, 2013
    Publication date: February 13, 2014
    Applicant: Furukawa Electric Co., Ltd.
    Inventors: Shigehiro TAKASAKA, Yu Mimura
  • Patent number: 7869014
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of the optical fiber are simultaneously specified.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: January 11, 2011
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Patent number: 7809223
    Abstract: A polarization-maintaining optical fiber includes a core region and a cladding region formed around the core region. The cladding region has a refractive index lower than a refractive index of the core region. A refractive index profile of the core region is either one of a step shaped or a concave shaped. The cladding region includes two holes formed in such a manner that a shortest distance from the core region is virtually zero at locations in opposite to each other across the core region.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: October 5, 2010
    Assignee: The Furukawa Electric Co., Ltd
    Inventors: Ryo Miyabe, Yu Mimura
  • Patent number: 7679744
    Abstract: The invention provides a Stokes parameter measurement device and Stokes parameter measurement method that enable high-precision measurement. The Stokes parameter measurement device comprises a polarization splitting device which comprises an optical element formed of a birefringent crystal material and which, by means of the optical element, splits signal light to be measured into a plurality of polarized light beams and adjusts the polarization state of one or more among the plurality of polarized light beams, and a light-receiving portion for performing photoelectric conversion of an optical component of the signal light split by and emitted from the polarization splitting device.
    Type: Grant
    Filed: December 4, 2007
    Date of Patent: March 16, 2010
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Mieko Yamagaki, Yu Mimura, Kazuyou Mizuno, Takeshi Takagi
  • Publication number: 20090273784
    Abstract: The invention provides a Stokes parameter measurement device and Stokes parameter measurement method that enable high-precision measurement. The Stokes parameter measurement device comprises a polarization splitting device which comprises an optical element formed of a birefringent crystal material and which, by means of the optical element, splits signal light to be measured into a plurality of polarized light beams and adjusts the polarization state of one or more among the plurality of polarized light beams, and a light-receiving portion for performing photoelectric conversion of an optical component of the signal light split by and emitted from the polarization splitting device.
    Type: Application
    Filed: December 4, 2007
    Publication date: November 5, 2009
    Applicant: The Furukawa Electric Co, Ltd.
    Inventors: Mieko Yamagaki, Yu Mimura, Kazuyou Mizuno, Takeshi Takagi
  • Patent number: 7529453
    Abstract: An optical fiber includes a core region and a cladding region. The cladding region includes a first cladding region on outer circumference of the core region, which includes a main-medium region and a sub-medium region having a refractive index lower than that of the main-medium region. The sub-medium region includes a plurality of inner sub-medium regions arranged along the outer circumference of the core region and a plurality of outer sub-medium regions arranged on outer of the inner sub-medium regions. The outer sub-medium regions have a lateral cross section larger than that of the inner sub-medium regions.
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: May 5, 2009
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Ryo Miyabe, Yu Mimura
  • Patent number: 7502540
    Abstract: An optical fiber includes a core region and a cladding region. The cladding region includes a first cladding region on an outer circumference of the core region, the first cladding region including a main-medium region and a sub-medium region having a refractive index lower than a refractive index of the main-medium region. The sub-medium region includes inner sub-medium regions arranged at four folds rotationally symmetric centering on the core region, and outer sub-medium regions arranged at four folds rotationally symmetric centering on the core region on an outer side of the inner sub-medium regions.
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: March 10, 2009
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Ryo Miyabe, Yu Mimura
  • Publication number: 20080292251
    Abstract: A polarization-maintaining optical fiber includes a core region and a cladding region formed around the core region. The cladding region has a refractive index lower than a refractive index of the core region. A refractive index profile of the core region is either one of a step shaped or a concave shaped. The cladding region includes two holes formed in such a manner that a shortest distance from the core region is virtually zero at locations in opposite to each other across the core region.
    Type: Application
    Filed: July 8, 2008
    Publication date: November 27, 2008
    Applicant: The Furukawa Electric Co., Ltd.
    Inventors: Ryo Miyabe, Yu Mimura
  • Publication number: 20080225276
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of the optical fiber are simultaneously specified.
    Type: Application
    Filed: February 12, 2008
    Publication date: September 18, 2008
    Applicant: The Furukawa Electric Co., Ltd.
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Patent number: 7424191
    Abstract: A method of simultaneously specifying the wavelength dispersion and nonlinear coefficient of an optical fiber. Pulsed probe light and pulsed pump light are first caused to enter an optical fiber to be measured. Then, the power oscillation of the back-scattered light of the probe light or idler light generated within the optical fiber is measured. Next, the instantaneous frequency of the measured power oscillation is obtained, and the dependency of the instantaneous frequency relative to the power oscillation of the pump light in a longitudinal direction of the optical fiber is obtained. Thereafter, a rate of change in the longitudinal direction between phase-mismatching conditions and nonlinear coefficient of the optical fiber is obtained from the dependency of the instantaneous frequency. And based on the rate of change, the longitudinal wavelength-dispersion distribution and longitudinal nonlinear-coefficient distribution of the optical fiber are simultaneously specified.
    Type: Grant
    Filed: October 13, 2006
    Date of Patent: September 9, 2008
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Masateru Tadakuma, Yu Mimura, Misao Sakano, Osamu Aso, Takeshi Nakajima, Katsutoshi Takahashi
  • Publication number: 20080159704
    Abstract: The present invention can easily realize an optical fiber and an optical transmission line that can propagate a light in a single mode while lowering a macro-bending loss and a PMD at the same time. An optical fiber 1 according to the present invention includes a cladding region 8 having a refractive index lower than that of a core region 2 on outer circumference of the core region 2. The cladding region 8 includes a first cladding region 3 in which a plurality of sub-medium regions 5a to 5d and 6a to 6h are arranged in multilayer.
    Type: Application
    Filed: September 13, 2006
    Publication date: July 3, 2008
    Applicant: THE FURUKAWA ELECTRIC CO, LTD.
    Inventors: Ryo Miyabe, Yu Mimura
  • Publication number: 20080124036
    Abstract: The present invention can easily realize an optical fiber and an optical transmission line that can propagate a light in a single mode while lowering a macro-bending loss against a small-diameter bending. An optical fiber 1 according to the present invention includes a first cladding region 3 having a refractive index lower than a refractive index of a core region 2 on outer circumference of the core region 2. Sub-medium regions 5a to 5f, 6a to 6f are arranged in multilayer in the first cladding region 3, which have a refractive index lower than a refractive index of a main-medium region of the first cladding region 3. The sub-medium regions 5a to 5f having a circular shape with a lateral cross section of a diameter d1 is arranged in an inner cladding area 3a of the first cladding region 3, and the sub-medium regions 6a to 6f having a circular shape with a lateral cross section of a diameter d2 (>d1) is arranged in an outer cladding area 3b of the first cladding region 3.
    Type: Application
    Filed: September 13, 2006
    Publication date: May 29, 2008
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Ryo Miyabe, Yu Mimura
  • Patent number: 7369232
    Abstract: An object is to accurately measure the Stokes parameters, without the occurrence of polarization fluctuations or PDL during the splitting of the incident light. When the incident light is made incident on a first-stage prism, the light is split into two first splitting light rays. Next, the first split light rays are respectively incident on a pair of prisms of a second stage. Each of the pair of first split light rays is split into two rays by a second-stage prism, to obtain four second split light rays.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: May 6, 2008
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Mieko Yamagaki, Yu Mimura, Kazuyou Mizuno, Takeshi Takagi