The Furukawa Electric Co., Ltd.

Yoshihiro Arashitani

Hiroki Tanaka

Yasuo Nakajima

Kenichi Suyama

Minoru Kasahara

Kouji Mochizuki

Minoru Saito

Hirotaka Watanabe

Kenji Yokomizo

Tomohiro Ishimura

Zyunpei Watanabe

Yutaka Hoshino

Masanobu Nakamura

Mitsunori Okada

Kouji Mochiduki

Masahiro Yabe

Takeshi Saito

Takeshi Yagi

Masanori Takahashi

Ryuichi Sugizaki

Hiroaki Ito

Yoshihiro Emori

Toshiaki Ozawa

Koichi Maeda

Shunichi Matsushita

Masaki Iwama

Eisuke Otani

Junpei Watanabe

Yukio Ishii

Toshio Miyahara

Takayoshi Ono

Zoltan Varallyay

Kazuyoshi Akizuki

Kunihiko Yujoubou

A multicore fiber includes: a plurality of first glass regions each including: a core portion; and a first cladding portion having a lower refractive index than a maximum refractive index of the core portion; and a cladding region formed on outer peripheries of the plurality of first glass regions, wherein compressive stress is applied to the plurality of first glass regions.

Multicore fiber

The present invention satisfies at least one of the condition of the degree of freedom of a primary layershown in the equation (I) and the condition of the rigidity of a secondary layershown in the equation (II). Thus, a coated optical fibercapable of suppressing transmission loss in a low temperature environment is provided, in which, even when an optical fiberhaving a large effective core cross-sectional area Aof the optical fiberat a wavelength of 1550 nm and having high microbend sensitivity is used, transmission loss in a low temperature environment can be suppressed.[Math. 1]β<600  (I)()×()≤1000  (II)

Coated optical fiber, optical fiber cable, and coated optical fiber ribbon

A bare optical fiber manufacturing method includes applying an ultraviolet curable resin applied around an optical fiber; and irradiating the ultraviolet curable resin with ultraviolet light emitted from semiconductor ultraviolet light emitting elements, by use of an ultraviolet irradiation device having plural ultraviolet irradiation units each having plural positions where the ultraviolet light is emitted toward the ultraviolet curable resin, the plural positions being arranged on the same circle, the plural ultraviolet irradiation units being arranged in a traveling direction of the optical fiber such that the optical fiber passes centers of the circles, at least two of the plural ultraviolet irradiation units being differently arranged with respect to circumferential direction angles thereof around an axis that is the traveling direction of the optical fiber.

Bare optical fiber manufacturing method

Provided is a coated optical fiber and an optical fiber cable capable of suppressing transmission loss (microbend loss) even in an optical fiber having high microbend sensitivity. In the present invention, the degree of freedom of a primary layerrepresented by the equation (I) and the rigidity of a secondary layerrepresented by the equation (II) are set in specific ranges, respectively. Thus, the present invention provides a coated optical fibercapable of suppressing the transmission loss even when an optical fiberhaving high microbend sensitivity such as a BI fiber having a large effective core cross-sectional area Aof an optical fiber is used. The present invention can be widely used as a coated optical fiberconstituting a coated optical fiber ribbon or as a coated optical fiberhoused in an optical fiber cable. Further, an optical fiber cable including such coated optical fibersenjoys the effect of the above-described coated optical fiber[Math. 1]&#x3b2;&#x2265;600&#x2003;&#x2003;(I)()&#xd7;()&#x2264;1,000&#x2003;&#x2003;(II)

Coated optical fiber and optical fiber cable

Provided is an optical fiber ribbon and an optical fiber cable, which are adaptable to manufacture at a high velocity, in the intermittent connecting type optical fiber ribbon obtained by adhering and connecting adjacent colored optical fibers by intermittent connecting portions. In an optical fiber ribbonof the present invention, since, in addition to polyol having a weight average molecular weight in a specific range, rheology control agent is contained in a specific range in a material forming an intermittent connecting portion, the Newtonian region between a low shear rate region and a high shear rate region of the material forming the intermittent connecting portioncan be adjusted. Thus, scattering of the material due to a centrifugal force generated by rotation of an application roll that applies the material at the time of manufacture and the like can be suppressed, and the application amount to colored optical fibercan be stabilized. In addition, the optical fiber ribboncan maintain suppression of such scattering and the like even in the manufacture at a high linear velocity.

Optical fiber ribbon and optical fiber cable

Ultraviolet irradiation device including circular irradiation units that focus light on a single point

A method for manufacturing an intermittent bonding type optical fiber ribbon which is capable of forming non-connection portions and intermittent connection portions between adjacent coated optical fibers formed into an optical fiber ribbon by performing a laser processing for the ribbon through irradiation with a pulse laser light, thereby making it possible to rapidly form the intermittent connection portions and the non-connection portions while maintaining high linear velocity of the coated optical fiber. The non-connection portions and the intermittent connection portions are formed in the obtained intermittent bonding type optical fiber ribbon through the irradiation with the pulse laser light, so the intermittent bonding type optical fiber ribbon becomes the intermittent bonding type optical fiber ribbon, which is capable of securing operability during collective connection and surely being subjected to an intermediate branching without damaging cable characteristics during high density mounting.

Method for manufacturing intermittent bonding type optical fiber ribbon and intermittent bonding type optical fiber ribbon

An optical fiber ribbon is intermittently connected in a length direction by an intermittent connection which includes a polyol having a weight-average molecular weight of 3000 to 4000 in a specific amount relative to the entire intermittent connection and which has Young's modulus at 23&#xb0; C. within a specific range. When collectively unitizing optical fiber ribbons to form an optical fiber cable, an optical fiber ribbon is formed which maintains advantages of the optical fiber ribbon and which prevents cracks of the intermittent connection and detachment of the intermittent connection from a colored optical fiber core when the cable is subjected to repetitive ironing.

An optical fiber including a glass core, and a polymer cladding formed around the glass core, the polymer cladding containing a mixture of a polymerizable composition and a silane coupling agent, and a fluorine-based ultraviolet curable resin. The mixture contains 5 to 95 parts by weight of the silane coupling agent based on 100 parts by weight of the total weight of the mixture. The fluorine-based ultraviolet curable resin alone has a refractive index in a range of 1.350 to 1.420 after ultraviolet curing. A component originated from the silane coupling agent is concentrated within a range of 20 &#x3bc;m or less in the polymer cladding from an interface between the glass core and the polymer cladding.

Optical fiber and method of manufacturing the same

A method of manufacturing an optical fiber wire includes applying ultraviolet curable resin onto the outer periphery of a traveling optical fiber, cooling the ultraviolet curable resin applied to the optical fiber using first cooled inert gas, and curing the ultraviolet curable resin by radiating ultraviolet rays on the ultraviolet curable resin that is cooled by the first cooled inert gas through an ultraviolet transparent tube.

Method of manufacturing optical fiber wire

A coated optical fiber, including a coating layer with a high elastic modulus even when a glass optical fiber is coated with resin by using an ultraviolet semiconductor light emitting element as a light source for curing resin and using a Wet-on-Wet method, is provided. A manufacturing method of the coated optical fiber includes: applying a first ultraviolet curable resin to a glass optical fiber; applying a second ultraviolet curable resin to the periphery of the first ultraviolet curable resin before curing the first ultraviolet curable resin; and irradiating the first and second ultraviolet curable resins with light in a wavelength range of 350 to 405 nm emitted from an ultraviolet semiconductor light emitting element, wherein the second ultraviolet curable resin contains a photopolymerization initiator that absorbs the light from the ultraviolet semiconductor light emitting element to generate radicals, and the photopolymerization initiator has photobleaching properties.

Coated optical fiber and method for manufacturing coated optical fiber

The purpose of the present invention is to provide, by a configuration or method different from conventional art, a coated optical fiber enabling reduced interface delamination between a glass fiber and a primary coating layer when the coated optical fiber is immersed in water, and a reduction of transmission loss increase. A coated optical fiber according to one embodiment of the present invention is provided with a glass fiber, a primary coating layer coated on the glass fiber, a secondary coating layer coated on the primary coating layer, and a colored layer coated on the secondary coating layer. The coated optical fiber is configured so that small water bubbles are generated substantially evenly within the primary coating layer when the coated optical fiber is immersed for 200 days in warm water of 60&#xb0; C.

Coated optical fiber, optical fiber ribbon, and optical cable

The present invention provides a two-layer structure colored optical fiber which includes a colored secondary coating layer improved in collectability and separability. The two-layer structure colored optical fiber in an embodiment of the present invention includes a glass optical fiber, a primary coating layer coating the glass optical fiber, and a colored secondary coating layer coating the primary coating layer. The secondary coating layer has such characteristics that a surface cure percentage is 99% or more at an infrared absorption peak of a wave number of 1407 cmand a surface kinetic friction force in Knot Test is less than 0.075 N.

Colored optical fiber

An optical fiber ribbon according to the present invention includes a collective coating layer containing an ultraviolet curable resin containing amorphous PPG and an amorphous monomer, the collective coating layer formed around coated optical fibers. The collective coating layer has an equilibrium elastic modulus of 12 MPa to 20 MPa, both inclusive, and a yield point elongation of 5% to 9%, both inclusive, and the adhesion between the collective coating layer and the outermost layers of the coated optical fibers is 12 N/cm to 15 N/cm, both inclusive.

Optical fiber ribbon

A colored optical fiber including a glass optical fiber; a primary coating layer that covers the glass optical fiber; a secondary coating layer that covers the primary coating layer; and a colored layer that coats the secondary coating layer. The relaxation modulus after 24 hours at 60&#xb0; C. of of the layers coated is 140 MPa or less.

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Tokyo, Japan

Yoshihiro Arashitani