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.

Abstract: Provided is an optical fiber in which a primary coating layer and a secondary coating layer are formed on an outer circumference of a bare optical fiber including a core and a cladding. A Young's modulus of the primary coating layer is 0.1 to 1.0 MPa, a relationship between lateral rigidity D and flexural rigidity H of the optical fiber as expressed by formulas below satisfies D/H2?3×1017 N?1 m?6, the primary coating layer contains 0.3 to 2.0 wt % of a photoinitiator including phosphorus, and the primary coating layer contains polypropylene glycol having a weight-average molecular weight of 1000 to 5000. The formulas include H = H g + H s = ? ? ? r g 4 ? E g + ? ? ( r s ? 4 - r p 4 ) ? E s ? ? and D = 0.897 ? E p + 2.873 ? ( E s - E p ) ? ( E p E s ) 0.8311 ? ( 2 ? r s - r p r s - r g ) 1.

Abstract: In an ultraviolet-curable resin composition for an optical fiber coating, the polarity parameter ET(30) of the resin composition is 47 to 61.

Abstract: Provided is an optical fiber in which a primary coating layer and a secondary coating layer are formed on an outer circumference of a bare optical fiber including a core and a cladding. A Young's modulus of the primary coating layer is 0.1 to 1.0 MPa, a relationship between lateral rigidity D and flexural rigidity H of the optical fiber as expressed by formulas below satisfies D/H2?3×1017 N?1m?6, the primary coating layer contains 0.3 to 2.0 wt % of a photoinitiator including phosphorus, and the primary coating layer contains polypropylene glycol having a weight-average molecular weight of 1000 to 5000. The formulas include H = H g + H s = ? ? ? r g 4 ? E g + ? ? ( r s ? 4 - r p 4 ) ? E s ? ? and D = 0.897 ? E p + 2.873 ? ( E s - E p ) ? ( E p E s ) 0.8311 ? ( 2 ? r s - r p r s - r g ) 1.

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: In an ultraviolet-curable resin composition for an optical fiber coating, the polarity parameter ET(30) of the resin composition is 47 to 61.

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.

Abstract: An optical fiber comprising: a glass fiber including a core and a cladding; and a coating layer coating an outer periphery of the glass fiber; wherein the coating layer includes a primary coating layer and a secondary coating layer, and a hardness at a depth of 200 nm from a surface of the secondary coating layer, HIT-200 nm, is 0.02 to 0.20 GPa as measured with a nano indenter.

Abstract: An optical fiber includes an optical transmission medium having 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, wherein a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C., and the primary resin layer comprises a cured product of an ultraviolet light curable resin composition containing a urethane (meth)acrylate oligomer, a monomer, a photopolymerization initiator and a ?-diketone compound, and tin.

Abstract: An optical fiber includes an optical transmission medium having 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, wherein the primary resin layer comprises a cured product of an ultraviolet light curable resin composition comprising a urethane (meth)acrylate oligomer, a monomer and a photopolymerization initiator, and a compound containing phosphorus and tin as constituent atoms; and a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C.

Abstract: An optical fiber includes an optical transmission medium having 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, wherein the primary resin layer comprises a cured product of an ultraviolet light curable resin composition comprising a urethane (meth)acrylate oligomer, a monomer and a photopolymerization initiator, and a compound containing phosphorus and tin as constituent atoms; and a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C.

Abstract: A manufacturing method of an optical fiber includes forming an optical fiber by forming a plurality of resin-coating layers around a glass fiber including a core part and a cladding part, and forming a marking on an outermost layer, which is a colored layer having pigment, of the plurality of resin-coating layers by melting or scorching a surface of the outermost layer with a laser.

Abstract: An optical fiber includes an optical transmission medium having 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, wherein a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C., and the primary resin layer comprises a cured product of an ultraviolet light curable resin composition containing a urethane (meth)acrylate oligomer, a monomer, a photopolymerization initiator and a ?-diketone compound, and tin.

Abstract: An optical fiber 1A comprises an optical transmission member 10 including a core 12 and a clad 14, a primary resin layer 22, and a secondary resin layer 24. The effective area of the optical transmission member 10 is 130 ?m2 or larger. The transmission loss of the optical transmission member 10 at a wavelength of 1550 nm is 0.165 dB/km or smaller. The Young's modulus of the primary resin layer 22 is 0.7 MPa or lower, and the Young's modulus of the secondary resin layer 24 is 600 MPa or higher and 1500 MPa or lower. The difference between the transmission loss when the optical fiber 1A is wound at a tension of 80 g around a bobbin on which a metal mesh member having vertical wires of a 50-?m diameter and horizontal wires of a 50-?m diameter are wound and spaced at a pitch of 150 ?m, and the transmission loss of an optical fiber coil is 1.0 dB/km or smaller.

Abstract: A process for producing an optical fiber including a glass fiber, a primary resin coating layer which covers the periphery of the glass fiber, and a secondary resin coating layer which covers the periphery of the primary resin coating layer, wherein the primary resin coating layer is formed by curing a curable resin composition which includes one or more oligomers, one or more monomers, and a reaction initiator, the curable resin composition containing a one-end-capped oligomer in an amount of 30% by mass or larger based on all the oligomers. The optical fiber produced by this production process does not deteriorate in low-temperature transmission loss, because the primary resin coating layer is inhibited from generating voids even when having a low Young's modulus.

Abstract: An optical fiber IA comprises an optical transmission member 10 including a core 12 and a clad 14, a primary resin layer 22, and a secondary resin layer 24. The effective area of the optical transmission member 10 is 130 ?m2 or larger. The transmission loss of the optical transmission member 10 at a wavelength of 1550 nm is 0.165 dB/km or smaller. The Young's modulus of the primary resin layer 22 is 0.7 MPa or lower, and the Young's modulus of the secondary resin layer 24 is 600 MPa or higher and 1500 MPa or lower. The difference between the transmission loss when the optical fiber 1A is wound at a tension of 80 g around a bobbin on which a metal mesh member having vertical wires of a 50-?m diameter and horizontal wires of a 50-?m diameter are wound and spaced at a pitch of 150 ?m, and the transmission loss of an optical fiber coil is 1.0 dB/km or smaller.

Abstract: Provided is an optical fiber which is provided with heat resistance and productivity and in which a transmission loss is suppressed even in a high-temperature environment. It has, on an outer periphery of a glass fiber composed of a core part and a cladding part, a coating layer made by crosslinking an energy-curable resin composition containing a silicon compound, in which the silicon compound contained in the energy-curable resin composition of the coating layer as an outermost layer has a specified structure having a cyclic silicone site having an epoxy group and a linear silicone site, with the content of the cyclic silicone site in the compound being from 10 to 30% by mass.

Abstract: A process for producing an optical fiber including a glass fiber, a primary resin coating layer which covers the periphery of the glass fiber, and a secondary resin coating layer which covers the periphery of the primary resin coating layer, wherein the primary resin coating layer is formed by curing a curable resin composition which includes one or more oligomers, one or more monomers, and a reaction initiator, the curable resin composition containing a one-end-capped oligomer in an amount of 30% by mass or larger based on all the oligomers. The optical fiber produced by this production process does not deteriorate in low-temperature transmission loss, because the primary resin coating layer is inhibited from generating voids even when having a low Young's modulus.

Abstract: An optical fiber 1 comprising a core layer 2 composed of a silica based glass, a clad layer 3 formed on the outer circumference of the core layer 2 by curing a curable resin composition, and an ink layer 4 formed around the clad layer 3, wherein adhesive force between the core layer 2 and the clad layer 3 being from 1.5 g/mm to 4.0 g/mm.

Abstract: An optical fiber sheet 10 includes an optical fiber 11 and a wire 12 that are arranged between a first sheet and a second sheet. The optical fiber 11 is a multi-mode optical fiber having a core of silica glass to which a refractive index adjuster is added, has a numerical aperture equal to or less than 0.30 and a flexural rigidity equal to or less than 0.50 N·mm2, and is bent to be arranged between the first sheet and the second sheet. The wire 12 intersects the optical fiber 11 between the first sheet and the second sheet.