Nec Corporation

Hussam Batshon

Fatih Yaman

Yoshihisa Inada

Takanori Inoue

Eduardo Rodriguez

Kohei Nakamura

Shinsuke Fujisawa

Takaaki Ogata

Ryuji Aida

Yue-Kai Huang

Naoto Ishii

Ezra Ip

Emmanuel Le Taillandier De Gabory

Yoshinari Takigawa

Ryu Kurahashi

Takigawa Yoshinari

Ankith Vinayachandran

Earthquake detection via fiber sensing is provided using using a supervisory path of submarine cables wherein the supervisory system/path of a submarine optical cable conveys portion(s) of an optical signal back to an origin location periodically—i.e., at every repeater location. Advantageously, since it is known where a returning signal is coming from, a resolution equivalent to an undersea span length may be determined—which is sufficient for wide area disturbances such as earthquakes. The returned signal is sufficiently strong such that the signal-to-noise ratio of a returned/received signal is not limited by the ASE noise of the amplifiers. The returned signal is much larger as compared to a normal distributed acoustic sensing (DAS) return signal since the return signal according to aspects of the present disclosure is directed backward via an optical coupler/reflector/circulator having a much larger coupling ratio as compared to normal Rayleigh back scattering utilized in DAS.

Fiber sensing using supervisory path of submarine cables

An optical communication system includes a first terminal device configured to receive first data, wherein the first terminal device is configured to generate an optical waveform based on the received first data. The optical system further includes an optical communication path configured to receive the optical waveform from the first terminal device. The optical system further includes a second terminal device configured to receive the optical waveform from the optical communication path, wherein the second terminal device is configured to output second data based on the optical waveform. At least one of the first terminal device or the second terminal device includes a nonlinear waveform distortion compensation device. The nonlinear waveform compensation device is configured to correct nonlinear waveform distortion resulting from the optical waveform propagating along the optical communication path, and the nonlinear waveform compensation device includes at least one recursive intermediate layer.

Method of equalizing waveform distortion, terminal device, and optical communication system

Aspects of the present disclosure are directed to systems, methods, and structures providing for the accurate measurement of guided acoustic-wave Brillouin scattering in optical fiber transmission systems and facilities.

Accurate measurement for guided acoustic-wave Brillouin scattering

Aspects of the present disclosure describe estimating/measuring core-cladding concentricity error in optical fibers. In sharp contrast to the prior art, our inventive method is based on measuring a seemingly unrelated property of fibers called guided acoustic wave Brillouin scattering (GAWBS). As we shall show and describe, by analyzing this GAWBS property we advantageously determine what level of CCCE is exhibited by the optical fiber.

Estimating core-cladding concentricity error in optical fibers using guided acoustic-wave Brillouin scattering

Aspects of the present disclosure describe systems, methods. and structures directed to an integrated 3-way branching unit switch module suitable for undersea application.

Integrated 3-way branching unit switch module having small footprint

Aspects of the present disclosure describe a three-way branching unit switch module having a small footprint suitable for application in an undersea application.

Three-way branching unit switch module having small footprint

Aspects of the present disclosure describe a method for estimating mode field distribution in optical fibers from guided acoustic-wave Brillouin scattering wherein light for which the optical mode-field distribution is determined remains in the optical fibers and the distribution is made for light inside the fiber, and not at a fiber/air interface or other perturbation points to the fiber resulting in a more accurate representation of the optical mode-field distribution in the fiber. Since light is always in the fiber during the determination, no complicated fiber preparation steps or procedures are required and the mode-field distribution is determined as an average distribution along the length of the fiber under test.

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Monroe, NJ, United States of America

Hussam Batshon