Sumitomo Electric Industries, Limited

Nippon Telegraph and Telephone Public Corporation

Yuji Kameo

Masao Yuto

Shigeru Tanaka

Toru Yamanishi

Katsuyuki Tsuneishi

Yuichi Toda

Masaaki Yoshida

Katsuji Sakamoto

Tatsuo Izawa

Yuichi Masuda

Chihaya Tanaka

Toru Kuwabara

Masakatsu Sugai

A method for producing an optical fiber which comprises steps of:

Method for producing optical fiber

A glass fiber for optical transmission comprising a glass fiber having provided thereon a first coating layer of a hardened resin and a second fluorine-containing resin layer formed by extrusion molding is disclosed. At least one of the first and second layers contains an adsorbable solid powder which is capable of adsorbing fluorine gas and/or hydrofluoric acid generated from the fluorine-containing resin during the extrusion molding. The glass fiber has an improved mechanical strength without adversely affecting transmission properties of the glass fiber.

Glass fiber for optical transmission

A wire-twisting machine for twisting individual wire-like structures into a cable, having a plurality of bobbins around which are wound the wire-like substance to be twisted, the bobbins being mounted on individual cradles which are supported at either end by disks secured to a common spindle, comprising: a drive mechanism having prime movers which are external to the bobbin-cradle assembly for controlling the speed of feeding the wire-like structure from its respective bobbin, thus resulting in constant wire-like structure tension, and another drive mechanism for controlling cradle rotation for fixing or adjusting the amount of twisting-back in said cable.

Wire-like structure twisting machine

A plastic fiber or an assembly thereof provided with first and second layers. The plastic fiber includes a core portion and a clad portion having lower refractive index than that of the core portion. The fiber is provided with the first coating formed over said clad portion. The first coating is formed of a saponification product of ethylene-vinyl acetate (EVA) copolymer, and the second coating is formed over said first coating and is made of a thermoplastic resin.

Coated plastic optical fiber

Two gaseous raw glass materials containing dopants to provide different refractive indices and borne by an argon carrier are jetted from the central or inner and first concentric nozzles 11, 12 of a five tip burner 1; an argon shield is supplied through the second concentric nozzle 13, and hydrogen and oxygen are supplied through the third and fourth concentric nozzles 14, 15, respectively. Soot-like glass particles 4 are formed by flame hydrolysis and deposited on the lower end of a start rod 3 which is gradually rotated and withdrawn to thus grow a cylindrical preform 2. The intermixing of the particles formed from the two glass materials produces a preform having a substantially parabolic radial index of refraction distribution, which characteristic is retained in an optical communication fiber formed by sintering and drawing the preform.

Method for manufacturing an optical fiber preform

Growing community of inventors

Kanagawa, Japan

Yuji Kameo