Multi-parameter distributed fiber sensing system based on hybrid Rayleigh and Brillouin scattering

Abstract

The integration of Rayleigh and Brillouin scattering in a hybrid sensor system has revolutionized the field of distributed fiber optic sensing. This hybrid sensor system provides a strong and all-encompassing solution for monitoring multiple physical parameters, including strain, temperature, and vibrations along the sensing fiber length by combining the strengths of both scattering phenomena. We present a hybrid multi-parameter distributed sensing system in this paper that is based on the Brillouin and Rayleigh scattering mechanisms. Utilizing a single-end access to the sensing fiber, we measured acoustic vibrations based on phase-sensitive optical time domain reflectometry (Φ-OTDR), whereas we employed a Brillouin optical time reflectometry (BOTDR) for strain and temperature monitoring. The experimental results demonstrate the effectiveness of the hybrid sensor system to achieve simultaneous and independent measurements over a 25 km long single-mode silica fiber at 3 m spatial resolution. Furthermore, we used a large effective area fiber (LEAF) for simultaneous and discriminative strain, temperature, and vibration monitoring in order to get around the cross-sensitivity between the strain and temperature in the BOTDR system. A variety of applications, such as the structural health monitoring of buildings, bridges, and oil and gas pipelines, industrial process control, security, and surveillance, can be served by the suggested multi-parameter hybrid distributed sensor system.