Enhancement of DAS sensitivity with acoustic metasurface

Distributed acoustic sensing (DAS) technology converts the existing fiber optic telecom cables or customized sensing cables into dense microphone arrays. Despite the research undertaken on cable structures, materials, and DAS interrogator, the adoption of passive acoustic manipulation array for enhancing acoustic sensitivity remains unexplored. In this study, we present a novel concept for improving the sensitivity of DAS with acoustic metasurface. The tapered labyrinthine structures are utilized in the construction of the ‘0’ a nd ‘1’ elements of the coding meta surface , which constitutes an acoustic lens. The sensitivity enhancement is achieved through the focusing of incident waves after the manipulation of acoustic metasurface. The simulated and experimental results demonstrate that the DAS sensitivity is significantly enhanced by approximately 10 dB across a frequency range of 810 Hz. This work demonstrates the feasibility of an acoustic metasurface-based DAS and its potential for applications in the detection of weak airborne, or underwater acoustic signals.