BOTDA sensing system employing a tunable low-cost Brillouin fiber ring laser pump-probe source

In this paper we show a Brillouin optical time-domain analysis (BOTDA) sensing system experiment employing a tunable narrow-linewidth dual pump-probe source based on modified Brillouin ring laser technology. The developed cost-effective source generates a tunable pump-locked probe light, with suitable wavelength shift, large tuning range (∼200 MHz), narrow linewidth (<2.5 MHz) and adequate power (∼0.5 mW). The developed source was hence employed in BOTDA system experiments providing distributed sensing over ∼10 km single mode optical fiber, and attaining strain and temperature resolutions of ∼10με and ∼0.5 °C respectively, indicating the pump-probe source as an efficient and cost-effective solution for BOTDA avoiding high-frequency signal generators or complex locking techniques.