BOTDA Sensing Employing a Modified Brillouin Fiber Laser Probe Source

A theoretical and experimental study has been carried out on a tunable dual pump-probe optical source for distributed Brillouin optical time-domain analysis (BOTDA). The developed source exploits a modified Brillouin ring laser technology and is capable of a tuning range of ~200 MHz without using phase-locked loop or optical sideband generation techniques, and exhibits a linewidth smaller than 2.5 MHz and ~0.5 mW power. In BOTDA experiments, the proposed source has demonstrated to be an efficient solution enabling distributed sensing over 10 km single mode fiber with a spatial resolution of ~4 m, and a strain and temperature resolutions of ~10 με and ~0.5 °C respectively.