Sumitomo Electric Industries, Limited

Nippon Telegraph and Telephone Corporation

Ichiro Yoshimura

Katsuya Nagayama

Yoichi Ishiguro

Yasuo Matsuda

Haruhiko Aikawa

Nobuyuki Yoshizawa

Yutaka Katsuyama

Toshifumi Hosoya

Shinji Ishikawa

Hiroo Kanamori

Yuji Kobayashi

Yutaka Wada

Yuichi Ohga

Yoshiki Chigusa

Horoshi Yokota

A winding reel for optical fiber is provided with a drum and a flange. The flange is provided with first and second slits therein for receiving leading and trailing (frontward and rearward) portions of the optical fiber. The length of the slit that receives the forward end of the optical fiber extends from the outer periphery of the flange to the surface of the drum. The slit for receiving the rearward end of the optical fiber is shorter than the forward end receiving slit. The rearward end receiving slit extends from the outer periphery of the flange inwardly a distance such that the slit does not reach a position at which a maximum amount of optical fiber wound on the winding reel is located.

Slitted winding wheel for optical fiber

An apparatus for manufacturing a hermetically coated optical fiber having a single reaction chamber into which a fare fiber and raw gas are to be introduced for applying a hermetic coating to the bare fiber while the bare fiber passes through the reaction chamber is characterized by that the reaction chamber has a plurality of inlet tubes to introduce the raw gas, and the plurality of inlet tubes open to the reaction chamber at different positions from each other in a direction of movement of the bare fiber passing through said reaction chamber.

Method for manufacturing a hermetically coated optical fiber

A method, for screening an optical fiber, and an apparatus for carrying out the method, in which two sucking nozzles and a tape sticking device are provided to automatically perform processing of the end portions of the optical fiber; and an automatic fiber transporting/mounting device is provided to transport the succeeding portion of the optical fiber to the winding roll and mount, it on the winding roll; dancer rolls are provided in the longitudinal direction of an arm; and supporting rolls are movable between the path line of the optical fiber and a position removed from the path line.

Method for screening optical fiber and apparatus for carrying out method

There is provided a process of melt drawing an optical fiber from a preform therefor in which a heating furnace comprising a muffle tube inside thereof through which the optical fiber is passed is provided immediately below a melt drawing furnace to further draw the optical fiber while heated, and an interior of the muffle tube is kept in an atmosphere selected from the group consisting of an inert atmosphere, an atmosphere comprising oxygen gas and an atmosphere comprising hydrogen gas.

Process of drawing optical fiber

A hermetic coated optical fiber is produced by preparing a bare optical fiber by melting and drawing an optical fiber preform in a fiber drawing furnace and introducing the bare optical fiber in a reactor in which a raw material gas is introduced and forming a hermetic coating film around a surface of the bare optical fiber by a chemical vapor deposition method or pyrolysis in the reactor, wherein a part of an inert gas for purging the fiber drawing furnace which has been heated by a heater equipped in the furnace is exhausted and a rest of the inert gas is introduced in the reactor for diluting the raw material gas.

Method for producing hermetic coated optical fiber

Apparatus for producing hermetic coated optical fiber

There is provided a drawing process for producing an optical fiber which comprises drawing the optical fiber from a preform therefor under tension to form the optical fiber while heating and melting the preform, wherein an outer diameter of the optical fiber on which no coating has been provided is measured at a position at which shrinkage of the outer diameter of the optical fiber, while stretched, is not larger than 0.5% and drawing conditions are controlled based on the deviation of the measured diameter from a preselected outer diameter.

Method for controlling fiber diameter during optical fiber drawing

A furnace comprising a cylindrical heater and a cylindrical insulation around the heater, wherein the insulation has anisotropy in heat transfer and a direction along which the thermal conductivity of the insulation is small corresponds to a direction along which temperature gradient within the insulation is steep. The insulation is formed of plural anisotropic parts arranged such that the direction along which thermal conductivity is low of one part blocks heat transfer from a direction along which the thermal conductivity of another part is high.

Growing community of inventors

Yokohama, Japan

Ichiro Yoshimura