Repeater design for distributed acoustic sensing on multispan fiber links
AssigneeNEC Laboratories America, Inc.
InventorsEzra IP, Yue-Kai HUANG, Fatih YAMAN, Shinsuke FUJISAWA
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Abstract
Aspects of the present disclosure are directed to alternative repeater design(s) that advantageously improve signal-to-noise of distributed acoustic sensing (DAS) systems using coherent detection of Rayleigh backscatter in multi-span links including inline amplification that may be employed—for example—in undersea submarine systems. The repeater designs incorporate Rayleigh combine units (RCU) and Rayleigh drop units (RDU) to reduce Rayleigh backscatter loss as Rayleigh signal(s) is/are routed to a link that propagates the backscatter signal in an opposite direction relative to interrogation pulse(s).
Claims10
A distributed optical fiber sensing/distributed acoustic sensing system comprising:
- a length of bi-directional optical fiber cable having multiple spans of fibers with inline optical amplifiers positioned after each span, said cable configured such that at least one fiber propagates light in a first direction and at least one fiber propagates light in a second direction, said second direction counter-propagating opposite to the first direction;
- a distributed optical fiber sensing/distributed acoustic sensing interrogator in optical communication with the length of bi-directional optical fiber cable including a fiber that propagates light in the first direction and a fiber that propagates light in the second direction;
- an intelligent analyzer configured to analyze DFOS sensing data received by the DFOS interrogator system;
- and
- one or more repeaters located at point(s) along the length of the optical fiber cable, said repeaters including a plurality of Rayleigh combine units (RCUs) and a plurality of Rayleigh drop units (RDUs)
Dependencies are inferred from the claim text.