Suppression of amplitude fluctuation in Brillouin optical fiber reflectometry employing polarization beam splitter and pre-amplification technique

We propose and validate the suppression effect on amplitude fluctuation in Brillouin optical time domain reflectometry sensing system with a polarization beam splitter and pre-amplification technique. The p- and s-components of local oscillator interfere respectively with two halves of Brillouin scattering amplified by a Erbium doped fiber amplifier. Theoretical analysis indicates that the polarization influence on the beat amplitude is eliminated with the proposed scheme; and experimental results show that the amplitude variation along the sensing fiber could be extracted accurately, and the temperature sensing error is about 5%. The proposed method is helpful to improve the measurement accuracy of the BOTDR sensing system.