Large-scale fiber interferometric sensor arrays with multiple optical amplifiers

Many applications require using common input and output fibers to support a large number of interferometric fiber sensors located far from the receiving electronics. Passive multiplexing of sensors is limited by splitting and dissipative losses to approximately 10 sensors per pair of fibers. A large scale array (200-1000 sensors) will thus require 40-200 telemetry fibers, which is unmanageable in practice. We report a novel method for multiplexing hundreds of sensors per pair of fibers, which incorporates fiber amplifiers into a time-domain multiplexed array with a ladder topology