US 12,480,808 B2
Laser frequency drift compensation in forward distributed acoustic sensing
Junqiang Hu, Davis, CA (US); and Yue-Kai Huang, Princeton, NJ (US)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on Jan. 19, 2024, as Appl. No. 18/417,798.
Claims priority of provisional application 63/480,549, filed on Jan. 19, 2023.
Prior Publication US 2024/0247974 A1, Jul. 25, 2024
Int. Cl. G01H 9/00 (2006.01); G01D 5/353 (2006.01)
CPC G01H 9/004 (2013.01) [G01D 5/35361 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method for laser frequency drift compensation in forward distributed acoustic sensing, the method comprising:
receiving an optical signal by a coherent optical receiver;
coherently detecting the optical signal such that a complex output having two polarizations X and Y, are produced;
performing frequency drift tracking on the complex output;
performing phase extraction on the frequency drift tracked complex output;
wherein the optical signal is a distributed fiber optic sensing optical signal.