Anti-resonant hollow-core optical fiber as a Fabry-Pérot interferometric high-performance cavity-enhanced photoacoustic sensing

Abstract

This paper reports for the first time a highly sensitive cavity-enhanced photoacoustic sensor constructed based on anti-resonant hollow-core fibre (AR-HCF) with acousto-optic transducer thin film, which shows great potential in photoacoustic sensing applications. In this design, the structure improves the reflectivity of the resonance cavity by introducing a resonance cavity enhancement mechanism that extends the time to capture light with a cavity fineness of 55, increasing the acoustic pressure sensitivity of the optical resonance cavity by more than an order of magnitude. The unique features of this all-fibre optic sensing architecture are its high sensitivity, low-loss characteristics, excellent stability, and the significant advantages of the sensor in terms of size and cost. This opens up new avenues for the development of photoacoustic sensing technology.