Fujikura Limited

Hiroyuki Sawano

Takahiro Hamada

Yukinari Shirako

Koichi Harada

Munehisa Fujimaki

Kenji Yamashiro

Shoichiro Matsuo

Kuniharu Himeno

Hideo Suzuki

Masayoshi Yamanaka

Matsuhiro Miyamoto

Shunichirou Hirafune

Kazunaga Kobayashi

Yasuyuki Sugawara

Hiroshi Kutami

Masaru Itoh

Yutaka Kurosawa

Nobuyasu Sato

An optical fiber processing apparatus comprises reactors (and) that accommodate optical fiber, a single suction pump () having an intake port () and an outlet port (), a storage chamber () into which deuterium containing gas is delivered, and a circuit portion () including a plurality of valves disposed on a plurality of passages connecting the reactors, the suction pump and the storage chamber. The circuit portion includes a first channel for returning deuterium containing gas inside a reactor chamber to the storage chamber, a second channel for delivering air to the reactor chamber thereby rendering the pressure inside the reactor chamber atmospheric pressure, a third channel for decompression of the reactor chamber and a fourth channel for supplying deuterium containing gas in the storage chamber into the reactor chamber.

Optical fiber processing apparatus

A treatment method for an optical fiber including accommodating an optical fiber inside a treatment chamber; introducing a deuterium containing gas into the treatment chamber; and in a deuterium treatment step, exposing the optical fiber to atmosphere of the deuterium containing gas. In the deuterium treatment step, a deuterium concentration D in the treatment chamber during the deuterium treatment is calculated from an initial value A of a deuterium concentration in the deuterium containing gas inside the treatment chamber, a concentration B of oxygen in an ambient atmosphere of the treatment chamber, and a concentration C of oxygen in the deuterium containing gas inside the treatment chamber, and the deuterium concentration in the treatment chamber is controlled based on the deuterium concentration D calculated. Other gases such as hydrogen containing gas or nitrogen containing gas may also be used according to the invention.

Treatment method for optical fiber

A method of treating optical fiber includes at least a first step of creating a reduced-pressure atmosphere in a space which holds the optical fiber, and a second step of introducing to the space a deuterium-containing gas so as to expose the optical fiber to the gas.

Method for treating optical fiber and apparatus for treating optical fiber

A single-mode optical fiber has a cut-off wavelength of 1260 nm or less, a zero-dispersion wavelength in the range of 1300 nm to 1324 nm, a zero-dispersion slope of 0.093 ps/nm/km or less, a mode field diameter at a wavelength of 1310 nm in the range of 5.5 &#x3bc;m to 7.9 &#x3bc;m, and a bending loss of 0.5 dB or less at a wavelength of 1550 nm, the bending loss being produced when the fiber is wound around a 10-mm radius for 10 turns.

Single-mode optical fiber

A loose tube optical fiber cable with SZ stranding in which the units receive two or more laminated multicase ribbons stranded toward a central member with the stranding direction reversed at specific intervals. These multicase ribbons are twisted in the same direction as the stranding of the tube units, and a reverse stranding angle of the tube units is selected to be a value within a specific scope.

Optical fiber cable containing ribbon fibers

A water penetration-detecting apparatus includes an optical fiber sensor having an optical fiber, and a water-absorbent material disposed along the optical fiber in contiguous relation to the fiber. The water-absorbent material, when absorbing water, expands volumetrically so as to apply a pressure to an outer peripheral surface of the optical fiber to bend the fiber. A detecting means is connected to the optical fiber sensor for detecting a bending of the optical fiber.

Water penetration-detecting apparatus and optical fiber cable using same

Growing community of inventors

Sakura, Japan

Hiroyuki Sawano