US 12,442,681 B2
Distributed fiber optic sensing enabled self-coherent detection for data centers
Yue-Kai Huang, Princeton, NJ (US); and Ezra Ip, West Windsor, NJ (US)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on Oct. 16, 2022, as Appl. No. 17/966,856.
Claims priority of provisional application 63/256,799, filed on Oct. 18, 2021.
Prior Publication US 2023/0119927 A1, Apr. 20, 2023
Int. Cl. H04B 10/63 (2013.01); G01H 9/00 (2006.01); H04B 10/2537 (2013.01); H04B 10/61 (2013.01)
CPC G01H 9/004 (2013.01) [H04B 10/2537 (2013.01); H04B 10/65 (2020.05)] 9 Claims
OG exemplary drawing
 
1. A dual-fiber, bidirectional, fiber optic communications link supporting distributed fiber optic sensing (DFOS), said communications link comprising:
a pair of optical fibers optically connecting a pair of transponders, the pair of optical fibers configured such that one of the optical fibers of the pair conveys optical signals in one direction, while the other one of the optical fibers of the pair conveys optical signals in an opposite direction;
wherein each individual one transponder of the pair of transponders is configured to perform self-coherent detection by using a local oscillator (LO) of the other one of the pair of transponders to perform demodulation; and
each individual one transponder of the pair of transponders is configured to transmit data signals in a counter-propagating manner with respect to a LO used for demodulation;
SAID COMMUNICATIONS LINK CHARACTERIZED BY:
a DFOS interrogator in optical communications with the pair of transponders and optical fibers, said DFOS interrogator configured to generate sensing signals for transmission by one of the transponders, wherein the sensing signals are transmitted along with any transmitted data;
wherein the sensing signals and the data signals are generated using a same digital-to-analog converter.