Abstract: An optical fiber comprises a glass fiber comprising a core and a cladding, and a coating resin layer covering the outer periphery of the glass fiber, wherein the average linear expansion coefficient of the coating resin layer at ?50° C. or more and 0° C. or less is 3.3×10?5/° C. or more and less than 9.0×10?5/° C.

Abstract: A resin composition comprises: a base resin containing an oligomer, a monomer, and a photopolymerization initiator; and inorganic oxide particles, wherein the inorganic oxide particles are lump-shaped aggregated particles, and the volume average particle size of the inorganic oxide particles measured by an X-ray small angle scattering method is 5 nm or more and 800 nm or less.

Abstract: A method for manufacturing an optical fiber includes: melting an optical fiber preform and drawing a glass fiber; applying a resin composition to an outer periphery of the glass fiber; and curing the resin composition applied, wherein an amount of eccentricity of a central axis of the glass fiber, in a cross section perpendicular to the central axis of the glass fiber, from a central axis relative to an outer periphery of the resin composition or an outer periphery of a coating resin layer formed by curing the resin composition is measured at 50 points or more over a length range of 50 m or more of the glass fiber, and wherein the resin composition is applied such that a mean value a and a standard deviation a of the amount of eccentricity satisfy a+3??10 ?m.

Abstract: An optical fiber comprises a glass fiber comprising a core and a cladding; and a coating resin layer coating the glass fiber, wherein the coating resin layer has a primary resin layer in contact with the glass fiber and coating the glass fiber and a secondary resin layer coating the outer periphery of the primary resin layer, the primary resin layer has a Young's modulus of 0.4 MPa or less at 23° C. and the primary resin layer has an outer diameter of 185 ?m or more and 202 ?m or less, the secondary resin layer has a glass transition temperature of 60° C. or more and 95° C. or less, and the difference between the average linear expansion coefficient of the coating resin layer in the range of 60° C. to 140° C. and the average linear expansion coefficient of the coating resin layer in the range of ?60° C. to 0° C. is 0.7×10?4/° C. or less.

Abstract: A method for manufacturing an optical fiber includes applying a first resin composition, forming a primary resin layer, applying a second resin composition, and forming a secondary resin layer. An ultraviolet LED used a light source in the forming the primary resin layer and the forming the secondary resin layer. In the forming the primary resin layer, an effective power consumption represented by formula (1) is 0.056 kWs or more and 0.230 kWs or less, ? n = 1 N Bn · ? ? n · tn ( 1 ) where N is a number of light sources, Bn [kW] is a rated power of an n-th light source, ?n is a predetermined rate of power of the n-th light source, and tn [s] is an irradiation time of the n-th light source.

Abstract: An eccentric state determining method which is performed by a controller and for determining a state of eccentricity of a coating of a glass fiber with respect to the glass fiber. The coating is formed around the glass fiber. The method includes acquiring measurement values for an outer diameter of the optical fiber at positions along a longitudinal direction of the optical fiber, calculating a standard deviation of the measurement values, and determining the state of the eccentricity based on the standard deviation.

Abstract: A method for producing an optical fiber coated with a UV-curable resin material around a glass fiber includes: a step of applying the UV-curable resin material to the periphery of the glass fiber; a step of passing the glass fiber coated with the UV-curable resin material through an interior of a cylindrical body (illustrated with a quartz tube) capable of transmitting UV light; a step of irradiating UV light from outside the cylindrical body by using a light source (illustrated with a UV bulb) to cure the glass fiber and form a coating; and a step of controlling (illustrated with a power controller) a power input to the light source so that a cure extent of the coating is constant based on the illuminance of the UV light from the light source and the illuminance of the UV light transmitted through the cylindrical body.

Abstract: An optical fiber includes a glass fiber and a coating resin layer surrounding the outer periphery of the glass fiber. The coating resin layer has a primary resin layer that surrounds the outer periphery of the glass fiber, and a secondary resin layer that surrounds the outer periphery of the primary resin layer. The primary resin layer has a thickness of 7.5 ?m or more and 17.5 ?m or less. The primary resin layer has a Young's modulus of 0.10 MPa or greater and 0.50 MPa or less at 23° C. The secondary resin layer has a thickness of 5.0 ?m or more and 17.5 ?m or less. The secondary resin layer has an outer diameter of 165 ?m or more and 175 ?m or less. The secondary resin layer has a Young's modulus of 1200 MPa or greater and 2800 MPa or less at 23° C.

Abstract: An optical fiber includes a glass fiber including: a core and a cladding; and a coating resin layer coating the glass fiber in contact with the glass fiber; wherein the coating resin layer has a primary resin layer coating the glass fiber in contact with the glass fiber and a secondary resin layer coating the primary resin layer, the primary resin layer contains a cured product of a first resin composition containing a photopolymerizable compound and a phosphine oxide-based photopolymerization initiator, the secondary resin layer contains a cured product of a second resin composition containing a photopolymerizable compound and a phosphine oxide-based photopolymerization initiator, and an amount of the phosphine oxide-based photopolymerization initiator remaining unreacted in the coating resin layer is 0.5 mass % or less.

Abstract: An optical fiber includes a glass fiber, and a resin coating layer covering an outer circumference of the glass fiber. In a spectrum acquired by measuring an amount of eccentricity of the glass fiber from a central axis based on an outer circumference of the resin coating layer at a plurality of measurement points set at a predetermined interval in an axial direction of the glass fiber and applying Fourier transform of a waveform representing the amount of eccentricity at each of the plurality of measurement points, a largest value of amplitude of the amount of eccentricity is 6 ?m or less.

Abstract: A method of manufacturing an optical fiber includes applying a curable resin composition containing a photopolymerization initiator so that an outer circumference of a glass fiber including a core and a cladding is coated, and forming a coating layer by radiating an ultraviolet ray to the curable resin composition and curing the curable resin composition. Forming the coating layer includes providing two or more non-radiation periods and intermittently radiating the ultraviolet ray three or more times so that a total time of the non-radiation periods is 0.010 seconds or more.

Abstract: A resin composition comprises: a base resin containing an oligomer, a monomer, and a photopolymerization initiator; and inorganic oxide particles, wherein the inorganic oxide particles are lump-shaped aggregated particles, and the volume average particle size of the inorganic oxide particles measured by an X-ray small angle scattering method is 5 nm or more and 800 nm or less.

Abstract: An optical fiber comprises a glass fiber comprising a core and a cladding; and a coating resin layer coating the glass fiber, wherein the coating resin layer has a primary resin layer in contact with the glass fiber and coating the glass fiber and a secondary resin layer coating the outer periphery of the primary resin layer, the primary resin layer has a Young's modulus of 0.4 MPa or less at 23° C. and the primary resin layer has an outer diameter of 185 ?m or more and 202 ?m or less, the secondary resin layer has a glass transition temperature of 60° C. or more and 95° C. or less, and the difference between the average linear expansion coefficient of the coating resin layer in the range of 60° C. to 140° C. and the average linear expansion coefficient of the coating resin layer in the range of ?60° C. to 0° C. is 0.7×10?4/° C. or less.

Abstract: The present disclosure relates to a resin composition for optical fiber coating, the resin composition including a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator; and inorganic oxide particles, in which a volume average particle size of the inorganic oxide particles as measured by a small angle X-ray scattering method is 800 nm or less, and a standardized dispersion of the volume average particle size is 60% or less.

Abstract: A resin composition for coating an optical fiber comprises a base resin containing an oligomer, a monomer, and a photopolymerization initiator, and hydrophobic inorganic oxide particles, wherein the oligomer comprises urethane (meth)acrylate and epoxy (meth)acrylate, and the mass ratio of the content of urethane (meth)acrylate to the content of epoxy (meth)acrylate is 0.25 or more.

Abstract: An optical fiber comprises a glass fiber comprising a core and a cladding, and a coating resin layer covering the outer periphery of the glass fiber, wherein the average linear expansion coefficient of the coating resin layer at ?50° C. or more and 0° C. or less is 3.3×10?5/° C. or more and less than 9.0×10?5/° C.

Abstract: The present disclosure relates to an optical fiber comprising a glass fiber including a core and a clad; a primary resin layer that coats the glass fiber by being in contact with the glass fiber; and a secondary resin layer that coats the primary resin layer, in which the secondary resin layer is formed from a cured product of a resin composition that includes a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator; and inorganic oxide particles, a volume average particle size of the inorganic oxide particles as measured by a small angle X-ray scattering method is 800 nm or less, and a standardized dispersion of the volume average particle size is 60% or less.

Abstract: A splicing structure of optical fibers in which optical fibers are coupled together, the optical fibers each comprising: a coated fiber portion including a glass fiber and a coating layer coating an outer periphery of the glass fiber; and a bare fiber portion where a certain length of the glass fiber is projected from an end face of the coating layer in an extending direction, wherein the glass fiber end faces of the bare fiber portion are fusion coupled together, and an outer periphery of the bare fiber portion is coated by a recoating layer, the recoating layer is a cured product of an ultraviolet light curable resin composition including a urethane (meth)acrylate oligomer and a mold release agent, and a content of the mold release agent is 0.01 to 1.5% by mass based on a total amount of the ultraviolet light curable resin composition.

Abstract: An optical fiber according to an embodiment comprises, as a structure suitable for large capacity transmission over a long haul, a core, a cladding having an outer diameter of 80 ?m or more and 130 ?m or less, a primary coating, and a secondary coating having elasticity higher than that of the primary coating and an outer diameter of 210 ?m or less. The optical fiber having the structure as described above has an MFD of 10 ?m or more at a wavelength of 1550 nm, a cable cutoff wavelength longer than 1260 nm, and a microbending loss of 0.6 dB/km or less at a wavelength of 1550 nm.

Abstract: An optical fiber includes an optical transmission medium comprising a core and a cladding; a primary resin layer disposed in contact with the optical transmission medium to coat the optical transmission medium; and a secondary resin layer coating the primary resin layer, and 1.1 ppm or less of a phosphorus compound and 2.5% by mass or less of a phenol compound based on the total amount of the primary resin layer are contained in the primary resin layer.