Nippon Telegraph and Telephone Corporation

Fujikura Limited

Kunihiro Toge

Tetsuya Manabe

Daisuke Iida

Tomokazu Oda

Hiroshi Takahashi

Yoshifumi Wakisaka

Shingo Ono

Kazuhiro Takizawa

Hiroyuki Oshida

Yusuke Yamada

Kazuo Hogari

Tatsuya Okamoto

Kazunori Katayama

Takaharu Matsuda

Chisato Fukai

Tomohiro Kawano

Tatsuya Ota

Hung Huu Luong

Hiroichi Katayose

Koji Ishizuka

Makoto Shinpo

The disclosure provides a monitoring control device and an optical power supply system in which a system capable of remotely controlling many optical power supply type optical nodes can be economically constructed. A monitoring control device according to the present disclosure includes control means for executing power supply and power supply time allocation for selecting a control target optical node based on the amount of stored energy of a plurality of optical nodes. According to the present disclosure, in a system that includes a monitoring control device installed in a power supply environment and one or a plurality of remotely arranged optical line switching nodes, optical power supply and control of a plurality of optical switches included in the nodes and management of an amount of stored power can be simultaneously implemented with a single laser. Thus, it is possible to provide an economical optical line switching node system.

Surveillance control device and optical power supply system

An object is to provide an optical fiber path search method, an optical fiber path search system, a signal processor, and a program that can be operated free of the effects of walls, supporting members, and the like so that only a signal generated by an acoustic wave propagating through the air can be extracted. An optical fiber path search system according to the present invention utilizes DAS and includes: a vibration sourceconfigured to provide an acoustic wave to a predetermined region; a light reflection measurement deviceconfigured to be connected to one end of an optical fiberand configured to measure vibration of a change in an optical path length from the other end of the optical fiberto a point in the optical fiberdue to the acoustic wave provided by the vibration source; and a signal processorconfigured to extract a signal component in a high frequency region higher than a preset cutoff frequency from a signal of the vibration of the change in the optical path length measured by the light reflection measurement deviceand calculate a distance between the vibration sourceand the point in the optical fiberusing the signal component.

Optical-fiber path searching method, optical-fiber path searching system, signal processing device, and program

A vibration distribution measurement system includes a frequency sweep light source that outputs frequency sweep light, an optical splitter that splits the frequency sweep light into probe light and local light, an optical mixer that mixes backscattered light from the sensing fiber as signal light with the local light, the backscattered light being obtained by causing the probe light to be incident on the sensing fiber, and an analysis unit that analyzes a beat signal obtained from output light of the optical mixer. The analysis unit estimates a distance offset from a measurement result obtained by measuring a distribution waveform of the signal light by measuring the beat signal at a measurement time sufficiently shorter than a cycle of the vibration of the sensing fiber, and measures a distribution of a vibration at any position by compensating for the distance offset.

Vibration distribution measuring system, vibration waveform analysis method, vibration waveform analyzing device, and analyzing program

It is intended to provide a phase measurement method and a signal processing device that are capable of reducing influence of noise of a measuring device without increasing the peak intensity of an incident light pulse when measuring the phase of scattered light in DAS-P. A phase measurement method according to the present invention causes wavelength-multiplexed pulse light to be incident on a measurement target optical fiber, produces a scattered light vector obtained by plotting scattered light from the measurement target optical fiber for each wavelength onto a two-dimensional plane having the in-phase component thereof on the horizontal axis and the orthogonal component thereof on the vertical axis, rotates the produced scattered light vector for each wavelength at each place in the measurement target optical fiber to align the directions of the vectors, generates a new vector by calculating the arithmetic average of the vectors having the aligned directions, and calculates the phase by using the values of the in-phase and orthogonal components of the generated new vector.

Phase measurement method and signal processing device

An optical fiber loss measurement device includes a unit configured to input pump light at a first frequency in a predetermined mode to a measurement target optical fiber in which a plurality of modes propagate from a first end, and input probe light at a second frequency to which a Brillouin frequency shift is applied to a second end, a Brillouin gain acquisition unit configured to measure an intensity of light output from the first end to acquire Brillouin gains in a longitudinal direction of the measurement target optical fiber using a BOTDA method, and a unit configured to measure a loss in the predetermined mode of the measurement target optical fiber, and the probe light is in a mode in which an electric field distribution in a cross section of the measurement target optical fiber is axisymmetric.

Optical fiber loss measurement device and optical fiber loss measurement method

An environmental property measurement apparatus includes a unit configured to receive probe light in a desired mode from one end of a measurement optical fiber, a unit configured to receive, from the other end of the measurement optical fiber, a light pulse in the desired mode as a pump light pulse with respect to the probe light, the light pulse having a frequency difference corresponding to a Brillouin frequency shift of the measurement optical fiber relative to the probe light on a high frequency side, and a unit configured to receive second probe light having the frequency difference corresponding to the Brillouin frequency shift of the measurement optical fiber relative to the probe light on a low frequency side from the other end of the measurement optical fiber, the second probe light being probe light with respect to the probe light in another mode different from the desired mode.

Environmental characteristic measurement device and environmental characteristic measurement method

An optical test system capable of accurately measuring a loss of each mode at each position of an optical fiber which propagates a plurality of modes is provided. An optical fiber loss measuring apparatus for measuring using an OTDR technique includes a crosstalk suppressing light input unit that inputs light of a different mode different from the predetermined mode, the different mode causing crosstalk to the probe light, to the target optical fiber to be measured through the near end as crosstalk suppressing light at a second frequency obtained by giving a frequency that is equivalent to a Brillouin frequency shift of the predetermined mode to a first frequency, a light separating unit that removes light of the second frequency from light that is output from the target optical fiber to be measured through the near end to separate light of the first frequency, and a propagation mode loss measuring unit that measures an intensity of the separated light to measure a loss of each propagation mode at each position of the target optical fiber to be measured.

Optical device loss measurement apparatus, and optical device loss measurement method

An object is to provide a propagation property analyzing apparatus that can alleviate the influence of an error caused by crosstalk, and accurately evaluate a few-mode optical fiber that multiplexes a plurality of modes, in a distributional and non-destructive manner. Provided is a propagation property analyzing apparatus that analyzes propagation properties of a few-mode optical fiber that multiplexes a plurality of modes, which is an optical fiber under test, in a lengthwise direction thereof, through Brillouin time domain analysis, the propagation property analyzing apparatus including: means for inputting probe light in a desired mode from a distal end of the optical fiber under test; means for inputting a light pulse that is in the desired mode and that has a frequency difference equivalent to a Brillouin frequency shift in the desired mode, relative to the probe light, from a proximal end of the optical fiber under test, as pump light corresponding to the probe light; and means for inputting a light pulse that is in another mode different from the desired mode and that has a frequency difference equivalent to a Brillouin frequency shift in the other mode, relative to the probe light, as secondary probe light corresponding to the probe light, from the proximal end of the optical fiber under test.

Propagation characteristic analysis device and propagation characteristic analysis method

Provided is an optical spectrum line width calculation method, apparatus, and program capable of calculating a spectrum line width of a laser to be measured from an optical interference signal generated by an optical interferometer having a delay line, based on a phase of the optical interference signal having a delay time longer than a delay time due to the delay line. The optical spectrum line width measurement apparatus includes a Mach-Zehnder interferometer, an optical receiver that receives an optical interference signal emitted from the Mach-Zehnder interferometer, an A/D converter that converts an analog electric signal output from the optical receiver into a digital electric signal, and a processing apparatus that processes the digital electric signal. Two light beams having a delay difference &#x3c4; are generated from light emitted from the laser to be measured, and an optical interference signal is generated by multiplexing the two light beams.

Optical spectral line width calculation method, device, and program

A distributed optical fiber vibration measurement device includes a phase constant difference computation unit causing the first backscattered light generated at the points of a plurality of optical fibers under test that are integrated to interfere with another light to obtain two AC components and determining a phase constant difference from the two AC components, a phase distribution data creation unit comparing amplitudes between the two AC components obtained by causing the first backscattered light generated at the points of the optical fibers under test to interfere with the other light and selecting, for each of the points, phase data regarding one of the two AC components having a larger amplitude to create phase distribution data with the phase data, and a vibration measurement unit identifying an optical path length difference between any two points of the optical fiber under test to measure vibration of the optical fiber under test.

Distributed optical fiber vibration measurement device and distributed optical fiber vibration measurement method

An optical fiber splicer includes a fiber fixing portion, a first optical fiber fixed to the fiber fixing portion, a clamp portion which is capable of holding and fixing an extending portion extended from the fiber fixing portion of the first optical fiber and a tip portion of a second optical fiber optically connected to the extending portion of the first optical fiber between a base member and a pressing member being openable and closable with respect to the base member, and a solid index matching material which is attached to a tip surface of the extending portion of the first optical fiber and is interposed between the first optical fiber and the second optical fiber.

Optical fiber connector

Amono-coated optical fiber that has a bending loss characteristic in which an optical loss increase at a bending radius 13 mm is 0.2 dB/10 turn or less, an optical fiber ribbon that includes two-dimensionally disposed resin portions for bonding the adjacent 2-fiber mono-coated optical fibers in plural places, the resin portions being disposed apart from each other in the longitudinal direction of the optical fiber ribbon and an optical fiber cable that includes a cable core portion that stores twisting of plural units where the mono-coated optical fibers constituting the optical fiber ribbon are collected.

Growing community of inventors

Musashino, Japan

Kunihiro Toge