Recent advances in signal-to-noise ratio enhancement techniques for distributed Brillouin fiber optic sensing

Brillouin Optical Time-Domain Detection Technology, including Brillouin optical time-domain reflectometry (BOTDR) and Brillouin optical time-domain analysis (BOTDA), has become a core solution for structural health monitoring of critical infrastructure. This review focuses specifically on signal-to-noise ratio (SNR) enhancement techniques for time-domain Brillouin distributed fiber sensing systems. It examines two complementary approaches: hardware architecture optimization and signal processing algorithms. At the hardware level, key innovations in optical pulse coding (OPC), distributed amplification, balanced detection, and pulse combination are analyzed. In signal processing, the evolution from classical denoising to modern deep learning methods is traced, with critical evaluation of performance trade-offs and implementation challenges. The study highlights the synergistic effects between hardware and algorithmic improvements, identifies remaining challenges, and outlines future research directions aimed at advancing the performance of practical time-domain Brillouin sensing systems.