Patents by Inventor Kazunori Mukasa

Kazunori Mukasa 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: 20210294030
    Abstract: An optical fiber includes: a central core portion; an intermediate layer formed around an outer circumference of the central core portion; a trench layer formed around an outer circumference of the intermediate layer; and a cladding portion formed around an outer circumference of the trench layer. Further, when, relative to the cladding portion, a relative refractive-index difference of the central core portion is ?1, a relative refractive-index difference of the intermediate layer is ?2, and a relative refractive-index difference of the trench layer is ?3, relationships ?1>?2>?3 and 0>?3 are satisfied and ?1 is equal to or greater than 0.34% and equal to or less than 0.40%, |?3| is equal to or less than 0.25%, and ?1×|?3| is less than 0.08%2.
    Type: Application
    Filed: June 9, 2021
    Publication date: September 23, 2021
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori MUKASA
  • Publication number: 20210231864
    Abstract: An object is to obtain an optical fiber having a small diameter and suppressing the increase of a microbending loss of the optical fiber. The optical fiber includes: a core portion made of silica glass; a cladding portion made of silica glass, the cladding portion covering the outer periphery of the core portion and having a refractive index smaller than a maximum refractive index of the core portion; and a coating portion covering the outer periphery of the cladding portion. The outer diameter of the cladding portion is 100 ?m or smaller, the relative refractive-index difference ?1 of the core portion is 0.5% or smaller, and the thickness of the coating portion is 10 ?m or larger.
    Type: Application
    Filed: April 16, 2021
    Publication date: July 29, 2021
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori MUKASA
  • Publication number: 20210223475
    Abstract: An optical fiber cable includes: a small-diameter optical fiber including a core and a cladding portion made of glass and having a cladding diameter of 120 ?m or less; a normal optical fiber that is optically connected to at least one end of the small-diameter optical fiber, includes a core and a cladding portion made of glass, and has a cladding diameter conforming to a standard of 125 ?m; an optical coupling mechanism provided between the small-diameter optical fiber and the normal optical fiber; and a sheath covering an outer periphery of the small-diameter optical fiber only, among the small-diameter optical fiber and the normal optical fiber. Further, the end of the small-diameter optical fiber is positioned outside the sheath.
    Type: Application
    Filed: April 2, 2021
    Publication date: July 22, 2021
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori MUKASA
  • Publication number: 20200400882
    Abstract: An optical fiber includes: a core portion made of glass; and a cladding portion made of glass, having a refractive index lower than the refractive index of the core portion, and positioned on an outer periphery of the core portion. Further, the cladding portion has an outer diameter smaller than 100 ?m, and the core portion has a relative refractive-index difference of 0.32% to 0.40% with respect to the cladding portion.
    Type: Application
    Filed: September 3, 2020
    Publication date: December 24, 2020
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori MUKASA
  • Publication number: 20200379168
    Abstract: A multi-core fiber includes: a plurality of cores; and a cladding portion formed around outer peripheries of the cores. Further, the cores each have a propagation characteristic conforming to any one of a plurality of standards for optical propagation characteristics, and of the cores, cores that are closest to each other conform to standards different from each other.
    Type: Application
    Filed: August 6, 2020
    Publication date: December 3, 2020
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori MUKASA
  • Publication number: 20200348463
    Abstract: A method of manufacturing a multicore fiber includes: an initial-preform forming process of forming an initial preform by arranging in an array a plurality of core rods each including a core portion and a cladding portion formed around outer periphery of the core portion; and an optical fiber manufacturing process of manufacturing an optical fiber from the initial preform. Further, the core rods include a plurality of holes, and the core rods are arranged in a manner that one hole is arranged between two core portion adjacent to each other in the initial-preform forming process.
    Type: Application
    Filed: July 17, 2020
    Publication date: November 5, 2020
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori Mukasa
  • Publication number: 20190219766
    Abstract: A tapered waveguide is optically connected to an end surface of an optical fiber bundle part, and has a tapered part that changes in outside diameter in a tapered shape. The fiber bundle part is optically connected to the end surface of the large-diameter side of the waveguide. The entire waveguide has a substantially uniform index of refraction. A delivery fiber is optically connected to the end surface on the small-diameter side of the waveguide. As with the fiber bundle part the delivery fiber passes through a hole in a capillary and is affixed. The capillaries are each affixed to a retaining member such that the fiber bundle part, the waveguide, and the delivery fiber are disposed on the same axis and optically connected. The waveguide is retained in a state floating from the retaining member, and the outside surface of the waveguide is not in contact with the retaining member.
    Type: Application
    Filed: March 22, 2019
    Publication date: July 18, 2019
    Inventors: Kengo Watanabe, Kazunori Mukasa, Tsunetoshi Saito, Yoshiki Nomura
  • 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: 9128234
    Abstract: A multi-core optical fiber includes a plurality of core portions, and a cladding portion positioned at outer peripheries of the plurality of core portions, the cladding portion having a refractive index lower than a maximum refractive index of each of the core portions, in which each of the core portions propagates light only with predetermined number, which is equal to or greater than 2, of propagation modes, and an effective core area at wavelength of 1550 nm of each of the propagation modes is equal to or greater than 120 ?m2.
    Type: Grant
    Filed: February 5, 2014
    Date of Patent: September 8, 2015
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori Mukasa
  • Patent number: 9128237
    Abstract: An optical fiber includes a core portion and a cladding portion that is formed on an outer periphery of the core portion and has a refractive index lower than a maximum refractive index of the core portion. Characteristics at a wavelength of 1550 nm are an effective core area of a fundamental propagation mode of equal to or larger than 120 ?m2, an effective core area of a first higher-order propagation mode of equal to or larger than 170 ?m2, and an effective refractive index of the first higher-order propagation mode of larger than the refractive index of the cladding portion by equal to or larger than 0.0005.
    Type: Grant
    Filed: August 8, 2013
    Date of Patent: September 8, 2015
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Kazunori Mukasa
  • Patent number: 9031372
    Abstract: A holey fiber includes: a core portion; an inner-cladding portion positioned at an outer periphery of the core portion, the inner-cladding portion having a plurality of inner holes formed in a layered structure around the core portion; and an outer-cladding portion positioned at an outer periphery of the inner-cladding portion, the outer-cladding portion having a plurality of outer holes formed in a layered structure around the inner-cladding portion. The inner holes are disposed to form a triangular lattice of which lattice constant ?1 is equal to or smaller than 2.0 ?m and to form equal to or greater than two layers. The outer holes are disposed to form a triangular lattice of which lattice constant ?2 is greater than the ?1 and equal to or larger than 3.0 ?m and to form equal to or greater than two layers. The overlap index is equal to or greater than 2.0%.
    Type: Grant
    Filed: March 10, 2014
    Date of Patent: May 12, 2015
    Assignee: Furukawa Electric Co,, Ltd.
    Inventor: Kazunori Mukasa
  • Patent number: 8861915
    Abstract: An optical fiber includes a core portion and a cladding portion that is formed around an outer periphery of the core portion and has a refractive index lower than a maximum refractive index of the core portion. As characteristics at a wavelength of 1550 nm, an effective core area in a fundamental propagation mode is 120 ?m2 or larger, an effective core area in a first higher-order propagation mode is 150 ?m2 or larger, an effective core area in a second higher-order propagation mode is 180 ?m2 or larger. An effective refractive index in the second higher-order propagation mode is larger than the refractive index of the cladding portion by 0.0002 or more, and an effective refractive index in a third higher-order propagation mode is less than the refractive index of the cladding portion.
    Type: Grant
    Filed: May 8, 2013
    Date of Patent: October 14, 2014
    Assignee: Furukawa Electric Co., Ltd.
    Inventor: Kazunori Mukasa
  • Patent number: 8811784
    Abstract: An optical fiber that propagates light over a use wavelength bandwidth of 100 nm or wider in a plurality of propagation modes is provided. The optical fiber has: a confinement loss equal to or less than 1 dB/km in each of the plurality of propagation modes over the use wavelength bandwidth; and a bending loss equal to or less than 100 dB/m in each of the plurality of propagation modes over the use wavelength bandwidth when the optical fiber is bent at a diameter of 20 mm.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: August 19, 2014
    Assignee: Furukawa Electric Co., Ltd.
    Inventor: Kazunori Mukasa
  • 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
  • Publication number: 20140193128
    Abstract: A holey fiber includes: a core portion; an inner-cladding portion positioned at an outer periphery of the core portion, the inner-cladding portion having a plurality of inner holes formed in a layered structure around the core portion; and an outer-cladding portion positioned at an outer periphery of the inner-cladding portion, the outer-cladding portion having a plurality of outer holes formed in a layered structure around the inner-cladding portion. The inner holes are disposed to form a triangular lattice of which lattice constant ?1 is equal to or smaller than 2.0 ?m and to form equal to or greater than two layers. The outer holes are disposed to form a triangular lattice of which lattice constant ?2 is greater than the ?1 and equal to or larger than 3.0 ?m and to form equal to or greater than two layers. The overlap index is equal to or greater than 2.0%.
    Type: Application
    Filed: March 10, 2014
    Publication date: July 10, 2014
    Applicant: Furukawa Electric Co., Ltd.
    Inventor: Kazunori MUKASA
  • Publication number: 20140153883
    Abstract: A multi-core optical fiber includes a plurality of core portions, and a cladding portion positioned at outer peripheries of the plurality of core portions, the cladding portion having a refractive index lower than a maximum refractive index of each of the core portions, in which each of the core portions propagates light only with predetermined number, which is equal to or greater than 2, of propagation modes, and an effective core area at wavelength of 1550 nm of each of the propagation modes is equal to or greater than 120 ?m2.
    Type: Application
    Filed: February 5, 2014
    Publication date: June 5, 2014
    Applicant: FURUKAWA ELECTRIC CO., LTD
    Inventor: Kazunori MUKASA
  • Publication number: 20140133816
    Abstract: A holey fiber includes a core portion and a cladding portion in which holes located in the outer periphery of the core portion and arranged around the core portion in layers, and a low refractive index layer having an internal diameter that is equal to or larger than four times a mode field radius of light in the core portion and having a refractive index lower than the core portion are formed.
    Type: Application
    Filed: January 17, 2014
    Publication date: May 15, 2014
    Applicant: Furukawa Electric Co., Ltd.
    Inventor: Kazunori MUKASA
  • Publication number: 20140029906
    Abstract: An optical fiber includes a core portion and a cladding portion that is formed on an outer periphery of the core portion and has a refractive index lower than a maximum refractive index of the core portion. Characteristics at a wavelength of 1550 nm are an effective core area of a fundamental propagation mode of equal to or larger than 120 ?m2, an effective core area of a first higher-order propagation mode of equal to or larger than 170 ?m2, and an effective refractive index of the first higher-order propagation mode of larger than the refractive index of the cladding portion by equal to or larger than 0.0005.
    Type: Application
    Filed: August 8, 2013
    Publication date: January 30, 2014
    Applicant: Furukawa Electric Co., Ltd.
    Inventor: Kazunori MUKASA
  • Publication number: 20130298380
    Abstract: A method of manufacturing a photonic bandgap fiber, which includes: a core portion; and a cladding portion that is formed around the core portion and has holes arranged to form a photonic crystal in which the core portion is a crystal defect, includes: forming a preform by inserting, into a jacket tube, hexagonal capillary tubes having tube-holes shapes and outer shapes that are both approximately hexagonal; and drawing the preform.
    Type: Application
    Filed: July 15, 2013
    Publication date: November 14, 2013
    Inventor: Kazunori MUKASA
  • Patent number: 8554038
    Abstract: A manufacturing method of a photonic band gap fiber which includes measuring a hole diameter d0 and a distance-between-holes ?0 in a preliminary experiment capillary body by first drawing a preliminary experiment preform, calculating a confinement loss to a normalized wavelength ?/? being a wavelength ? normalized by an optional distance-between-holes ? using a ratio d0/?0 and the optional distance-between-holes ? as design parameters, setting a distance-between-holes by calculating the set distance-between-holes ?1 to a desired transmission wavelength ?1 of a photonic band gap fiber to be manufactured using a value of the normalized wavelength ?/? in which the confinement loss becomes about a minimum value, and second drawing a preform for a photonic band gap fiber by using the same members as those of the preliminary experiment preform and by setting a distance-between-holes to the set distance-between-holes ?1, in a drawing temperature condition used for the first drawing.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: October 8, 2013
    Assignee: Furukawa Electric Co., Ltd.
    Inventor: Kazunori Mukasa