Fujikura Limited

Other

Tsuyoshi Shimomichi

Keiji Oohashi

Shinji Araki

Keiji Ohashi

Hideo Suzuki

Ryozo Yamauchi

Akira Wada

Keiko Mitsuhashi

Etsuo Ino

Kunihiko Fujiwara

Kazuhiro Takizawa

Yukio Hayashi

Masao Tachikura

Hirohito Watanabe

Yasuhiro Tamaki

Daigo Saito

Satoru Shiobara

Hajime Takemoto

Takeshi Honjo

Tetsuo Hayano

Katuyoshi Ishida

Kazunaga Kobayashi

An optical fiber cable that sustains reduced increase in transmission loss and optical fiber breakage when subject to external pressure exerted thereon, comprises an aggregate of elements including central buffer filaments disposed in the center part of the optical fiber cable and a plurality of optical fibers disposed around the central buffer filaments, as well as circumferential strength filaments disposed around the outer periphery of the aggregate of elements, and a sheath covering the circumferential strength filaments.

Optical fiber cable

The invention is an optical fiber sheet obtained by adhering together at least two sheets with an optical fiber placed therebetween, and placing a reinforcing tube over a portion of the optical fiber extending from an edge of the sheets, wherein the reinforcing tube is fixed to the sheets by bonding, with the reinforcing tube inserted between the sheets located up and below by an appropriate distance from an edge of the sheets.

Optical fiber sheet and optical fiber sheet production method

A distinctive optical fiber comprises an optical fiber core, distinctive layers, and a colored layer. A plurality of the distinctive layers including fine drops of ink having a specific particle size is disposed intermittently on the optical fiber core in the longitudinal direction of the optical fiber core. The colored layer is disposed on the distinctive layers and on the optical fiber core on which the distinctive layers are not disposed. The following five requirements are required for obtaining the distinctive optical fiber excellent in distinctiveness and with low transmission loss. The thickness of the colored layer is chosen so as to be larger than or equal to 2 &#x3bc;m and smaller than or equal to 10 &#x3bc;m. The thickness of the distinctive layers is chosen so as to be larger than or equal to 0.5 &#x3bc;m and smaller than or equal to 2.5 &#x3bc;m. The length of the distinctive layers is chosen so as to be larger than or equal to 1 mm and smaller than or equal to 15 mm. The interval of the distinctive layers is chosen so as to be in the range between 1 mm and 200 mm. The occupied ratio of the distinctive layers is chosen so as to be less than or equal to 20%. The major diameter of the fine drops of ink is chosen so as to be larger than or equal to 100 &#x3bc;m and smaller than or equal to 400 &#x3bc;m.

Optical fiber and optical fiber cable using the same

A resin liquid is provided which is used to produce an optical fiber coating layer which does not degrade over time in long-period transmission characteristics of the optical fiber. An optical fiber in which long-period transmission characteristics do not degrade is also provided. In order to achieve these objects, the present invention provides a resin liquid for an optical fiber coating layer containing at least one resin, wherein the resin liquid contains fewer than 500 pieces of extraneous material per 1 ml of the resin liquid, which have a minimum length of 0.5 &#x3bc;m or more and a hardness greater than a hardness of the resin liquid after curing.

Resin liquid for optical fiber coating layer

An optical fiber unit for air blown fiber installation, including an optical fiber wire; an inner coating layer formed on an outer periphery of the optical fiber wire with a modulus of elasticity ranging from 0.98 to 196 MPa; an outer coating layer formed on an outer periphery of the inner coating layer with a modulus of elasticity ranging from 196 to 1960 MPa; and a foamed plastic layer formed on an outer periphery of the outer coating layer.

Optical fiber unit for air blown fiber installation

Metal filaments such as steel wires which has Young's modulus of 10,000 kg/mm,are provided longitudinally on a UV curable resin coated optical fiber. A resin covering layer is then formed on a resultant structure by coating ultraviolet curing resin and then curing the resin, whereby resulting in an extremely small optical fiber cord having a finished diameter of about 250 &mgr;m.

Optical fiber cord, ribbon cord using the same and ribbon cord branch line

The present invention relates to a method for the fusion splicing of carbon coated optical fibers and to a method for providing reinforced performance of the spliced points. Concretely, carbon coated optical fibers are fusion spliced in an atmosphere containing less than 0.5 vol % of oxygen without the removal of the carbon coating. In order to minimize the amount of damage to the carbon coating resulting from the fusion, the decline in the failure probability of the optical fiber is controlled by means of applying moisture to the spliced part or by means of the adhesion of the oxidized carbon gases to the optical fiber. On the other hand, the carbon coating layer which was removed by oxidation at the time of the fusion splicing is recoated by means of a CVD reaction using a laser as a heat source. By means of this, the decline in the fatigue characteristics of the spliced part can be controlled.

Method for splicing and reinforcing carbon coated optical fibers

A method for manufacturing carbon coated optical fiber includes the steps of removing adherent foreign material from a surface of a bare optical fiber, and forming at least one carbon layer on the surface thereof using a chemical vapor deposition method. The first step is performed by heating and drying the surface of the bare optical fiber in a 80 to 150 degrees C. temperature region to vaporize the adherent foreign material while supplying an inert gas to the surface thereof so as to substitute the inert gas for the vaporized adherent foreign material. The second step is performed by thermally decomposing at least one hydrocarbon compound to obtain a thermal decomposate of the hydrocarbon, and depositing the thermal decomposate on the surface of the bare optical fiber. Also, disclosed is a method for manufacturing carbon coated optical fiber including the steps of cooling a surface of a bare optical fiber to a temperature no higher than 50.degree. C., and forming at least one carbon layer on the surface using a chemical vapor deposition method. The cooling step is performed by supplying a cooled inert gas to the surface of the bare optical fiber.

Method of cleaning and carbon coating optical fiber

Disclosed is a method for producing carbon-coated optical fiber including the steps of thermally decomposing a halogenated hydrocarbon compound to obtain a thermal decomposate of the halogenated hydrocarbon, and depositing the thermal decomposate on a surface of an uncoated optical fiber to form at least one carbon coating layer on the surface of the fiber. The halogenated hydrocarbon compounds include CClF.sub.3 , CCl.sub.2 F.sub.2 , CCl.sub.3 F, C.sub.2 Cl.sub.2 F and C.sub.2 ClF.sub.5. The deposition is performed at a temperature which is slightly below the thermal decomposition temperature. The method includes an optional step of coating at least one resin layer over a surface of the carbon coating layer.

Method for producing carbon-coated optical fiber

There is disclosed an optical fiber coated with a carbon layer in which carbon coating layer is formed by thermally decomposing a hydrocarbon or halogenated hydrocarbon compound having 15 or less carbon atoms. There is also disclosed an apparatus for producing the optical fiber coated with at least one carbon layer.

Growing community of inventors

Sakura, Japan

Tsuyoshi Shimomichi