Sumitomo Electric Industries, Limited

Hisashi Tanji

Itaru Sakabe

Hiroki Ishikawa

Eisuke Sasaoka

Toshiaki Kakii

Yoshinori Yamamoto

Atsushi Suzuki

Tomoyuki Hattori

Nobuhiro Akasaka

Keisuke Okada

Kazuaki Hamada

Kaoru Okuno

The present invention relates to a sensor or the like having a structure that enables accurate temperature measurement in a wide temperature range including a low-temperature region and is suitable for independently and accurately determining temperature variations and strains appearing in an object to be measured. The sensor comprises a laser light source, a sensor section that has a plurality of waveguides transmitting a laser light from the laser light source therethrough, a detecting section, and an analyzing section. The detecting section detects a plurality of Brillouin spectra obtained from the sensor section. The analyzing section determines at least one measurement value of a temperature in the sensor section and a strain generated in the sensor section, based on fluctuations of parameters defining the respective detected Brillouin spectra. In particular, the sensor section has a structure such that the variation of the Brillouin spectrum in response to a disturbance differs between the waveguides. Thus, by simultaneously monitoring the Brillouin spectra that varying a different manner in a plurality of waveguides, it is possible not only to measure accurately the temperature in a wide temperature range including a low-temperature region, but also to make distinction between the strain and temperature.

Sensor and disturbance measurement method using the same

A plurality of optical fibers are arranged in parallel and peripheries of the plurality of these optical fibers are integrally formed using a sheath. Here, the sheath is formed over the entire length of optical fiber ribbons and a flat portion of the sheath is formed substantially parallel to a common tangent of the neighboring optical fibers. A maximum value of a thickness of the optical fiber ribbons is set to a value which is larger than an outer diameter of the optical fibers by 40 &#x3bc;m or less. Due to such a constitution, it is possible to easily branch the optical fibers from the integrally formed optical fiber ribbons.

Optical fiber ribbon that is easily branched into individual optical fibers and optical fiber cable using the same

A communication cable having a communication wire and an armor including at least two synthetic resin layers, and protects the communication wire in a loose state. The communication wire protecting tube includes at least two synthetic resin layers, and inserts the communication wire in a loose state. The most hard resin layer of the armor has a crosswise or spiral annular groove or cut portion continuous in the longitudinal direction to reach the radially inner face, and the outermost layer of the armor is formed of a protective layer made of a softer resin than the hard resin layer. The adjoining edge portions of the annular groove or the cut portion come, when the communication wire is to be bent, into contact with each other so that it may be prevented from being bent to a predetermined or smaller bend radius.

Communication cable, and communication wire protecting tube

Growing community of inventors

Yokohama, Japan

Hisashi Tanji