Sensing range improvement of brillouin optical time domain reflectometry (BOTDR) using inline erbium-doped fibre amplifier

In this paper, we demonstrate sensing range improvement of Brillouin optical time-domain reflectometry (BOTDR) using an inline erbium-doped fibre amplifier to compensate the sensing fibre loss. In addition, a passive depolarizer is used based on the polarization beam splitter to suppress the polarization noise. The proof-of-concept is demonstrated experimentally using a 50 km sensing fibre with a 5 m spatial resolution. The strain and temperature errors at end of the sensing fibre are 23 με and 1.08°C, respectively.