US 12,332,394 B2
Fiber sensing using supervisory path of submarine cables
Fatih Yaman, Princeton, NJ (US); Yue-Kai Huang, Princeton, NJ (US); Ezra Ip, West Windsor, NJ (US); Hussam Batshon, Monroe, NJ (US); Eduardo Mateo Rodriguez, Tokyo (JP); Kohei Nakamura, Tokyo (JP); Takanori Inoue, Tokyo (JP); and Yoshihisa Inada, Tokyo (JP)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on May 31, 2022, as Appl. No. 17/829,284.
Claims priority of provisional application 63/195,305, filed on Jun. 1, 2021.
Prior Publication US 2022/0381932 A1, Dec. 1, 2022
Int. Cl. G01V 1/22 (2006.01); G01V 1/01 (2024.01); H04B 10/25 (2013.01)
CPC G01V 1/01 (2024.01) [G01V 1/226 (2013.01); H04B 10/25 (2013.01)] 1 Claim
OG exemplary drawing
 
1. An earthquake sensing method comprising:
providing a submarine/undersea fiber optic communications system, the fiber optic communications system comprising a forward fiber and a backward fiber, the forward fiber and the backward fiber each including a plurality of spans of optical fiber, each span of the plurality of spans having a repeater, each repeater configured to receive optical signals, separate a portion of the received optical signals, and redirect the separated portion to the backward fiber;
providing a sensor transmitter and a sensor receiver, the sensor transmitter in optical communication with the forward fiber, and the sensor receiver in optical communication with the backward fiber, the sensor transmitter configured to generate optical signals and apply the generated optical signals to the forward fiber, the sensor receiver configured to receive, from the backward fiber, portions of the generated optical signals separated by the repeaters; and
determining, from the received portions of the optical signals, seismic activity including earthquakes affecting the submarine/undersea fiber optic communication system;
wherein the sensor transmitter and sensor receiver operate using a double-pulse, double-differentiation technique.