Nippon Telegraph and Telephone Corporation

Chihiro Kito

Atsushi Nakamura

Hiroyuki Oshida

Daisuke Iida

Junichi Kawataka

Shingo Ono

An object of the present invention is to provide an optical access network that has high reliability for supporting information communication services and efficiently responds to difficult-to-predict optical fiber demand. An optical access network configuration according to the present invention includes an optical fiber cablethat is looped to connect a wiring sectionand an exchange officetogether (hereinafter, an upper loop), an optical fiber cablethat is looped and laid in each wiring section(hereinafter, a lower loop), and an optical fiber switching function unitinstalled at a connection pointbetween the upper loopand the lower loop. The optical fiber switching function unitis a wiring board or an optical switch which can be switched by connector connection. The wiring board or the optical switch may be remotely controllable.

Optical access network

An object of the present invention is to provide a Brillouin optical sensing device and an optical sensing method capable of reducing introduction costs. The Brillouin optical sensing device according to the present invention includes: a sensing fiberin which a plurality of optical fibers having Brillouin frequency shift characteristics different from each other are arranged in parallel; an optical measuring instrumentthat launches an optical pulse into at least two of the optical fibers of the sensing fiberto generate Brillouin scattering lights and measures a beat frequency of a beat signal between the Brillouin scattering lights at any position of the sensing fiber; and an arithmetic processing unitthat acquires a physical quantity of the sensing fiberat said any position based on the beat frequency acquired by the optical measuring instrument

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Musashino, Japan

Chihiro Kito