Low-noise distributed acoustic sensing using enhanced backscattering fiber with ultra-low-loss point reflectors

• DOI: 10.1364/oe.389212
• Publication Date: 2020-04-22T17:00:09Z
• Authors: Brandon Redding; Matthew J. Murray; Andrei Donko; Martynas Beresna; Ali Masoudi; Gilberto Brambilla
• Keywords: Distributed Acoustic Sensing; Backscatter (email)

We present a low-noise distributed acoustic sensor using enhanced backscattering fiber with series of localized reflectors. The point reflectors were inscribed in standard telecom fully automated system by focusing an ultra-fast laser through the cladding. provided reflectance -53 dB, significantly higher than Rayleigh level -70 dB/m, despite adding only 0.01 dB loss per 100 reflection points. constructed coherent φ-OTDR double-pulse architecture to probe fiber. Using this system, we found that enabled average phase noise -91 (re rad2/Hz), 20 lower sensors formed same are immune interference fading, exhibit high degree linearity, and demonstrate excellent non-local signal suppression (>50 dB). This work illustrates potential for low-cost enable low-noise, long-range sensing.