Fiber sensing using supervisory path of submarine cables

US12332394B2 · kind B2 · utility

Assignee

• NEC CORPORATION · JP

Inventors

• Fatih Yaman · Princeton, US
• Yue-Kai Huang · Princeton, US
• Ezra Ip · Princeton Colonial Park, US
• Hussam G. Batshon · Monroe, US
• Eduardo Mateo Rodriguez · Tokyo, JP
• Kohei Nakamura · Sakai, JP
• Takanori Inoue · Ebeye, US
• Yoshihisa Inada · Tokyo, JP

Key dates

• Filing date: May 31, 2022
• Grant date: Jun 17, 2025
• Expiry date: Nov 23, 2042

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B10/25
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

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.