Sumitomo Electric Industries, Limited

Toshio Oshima

Yasunori Saito

Osamu Ichikawa

Yoshiaki Nagao

Yoshiaki Terasawa

Shinji Endo

Toshiyuki Yamamoto

An optical fiber inspecting system comprises a waveform measuring unit for measuring an OTDR waveform for an optical fiber and a waveform evaluating unit for evaluating an anomaly within the optical fiber through a use of the measured waveform. The waveform evaluating unit comprises a calculating part and a detecting part. The calculating part calculates the gradient and the amount of change in gradient of the waveform at each time point by means of a gradient calculating section and a gradient change amount calculating section. The detecting part determines whether or not the gradient and the amount of change in gradient are within a defined allowable range of gradient and a defined allowable range of amount of change, respectively, by way of a gradient determining section and a gradient change amount determining section.

Method for selection of optical fiber and system for inspection of optical fiber

An optical fiber inspecting systemA comprises a waveform measuring unitfor measuring an OTDR waveform for an optical fiber F to be inspected and a waveform evaluating unitfor evaluating an anomaly within the optical fiber. The waveform evaluating unitcomprises a calculating partand a detecting partThe calculating partcalculates the gradient and the amount of change in gradient of the waveform at each time point. The detecting partdetermines whether or not the gradient and the amount of change in gradient are within a defined allowable range of gradient and a defined allowable range of amount of change, respectively. This realizes an optical fiber inspecting system, an inspection method and a selecting method, all of which enable to detect reliably an anomaly within an optical fiber through an OTDR waveform.

It is an object of this invention to provide a connection unit capable of improving transmission characteristics. The connection unit according to this invention is provided between a plurality of first optical fibers extending from an optical amplifier and a plurality of second optical fibers in an optical cable, and comprises one or more optical components to connect one first optical fiber to one second optical fiber. Each of the optical components includes third and fourth optical fibers that can be connected to one first optical fiber and one second optical fiber with low connection losses, respectively, and a loss adjusting section for adjusting a transmission loss. The transmission loss deviation in a plurality of optical transmission lines is adjusted to 0.005 dB/km or less.

Connection unit, optical fiber line unit, optical cable, and optical transmission system

In a waterproof optical fiber cable for use in a communication system, one or more optical fibers are loosely put in grooves formed along a spacer and a plurality of filled portions are formed in each of said grooves by being filled with dampproof material with a predetermined interval so as to provide a plurality of filled portions and unfilled portions alternately, whereby undesired local bending of the optical fibers can be prevented. Also a method of making the waterproof optical fiber cable having such filled portions and unfilled portions is disclosed.

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Yokohama, Japan

Toshio Oshima