A High-SNR Distributed Acoustic Sensor Based on ϕ-OTDR Using a Scalable Phase Demodulation Scheme Without Phase Unwrapping

We propose and experimentally demonstrate a high-SNR Distributed Acoustic Sensing (DAS) scheme using an array of Ultra-Weak Fiber Bragg Gratings (UWFBGs) with dynamic phase extraction in direct detection based on delayed interferometry and a scalable phase-generated carrier demodulation algorithm requiring no phase unwrapping.