Brillouin optical time-domain analysis enhanced by forward stimulated Brillouin scattering: proof-of-concept demonstration

Abstract

A distributed Brillouin optical time-domain analysis (BOTDA) sensor enhanced by forward stimulated Brillouin scattering (FSBS) based distributed Brillouin amplification (DBA) was proposed and presented. Due to co-propagating of pump and Stokes lights, the Stokes pulse is effectively amplified in front segment of fiber, resulting in flatter gain distribution. As a proof-of-concept, FSBS-DBA based BOTDA sensing with distance of ∼74.2 km, Brillouin frequency shift standard deviation of less than ∼2 MHz and spatial resolution of ∼10 m was demonstrated. This method is compatible and complementary with backward SBS-based DBA, and features better pumping efficiency than Raman amplification.

Distributed analysis of forward stimulated Brillouin scattering for acoustic impedance sensing by extraction of a 2nd-order local spectrum*

“…In addition, this striking effect has been extensively used for acoustic veloc-ity measurement, [36] fiber diameter estimation, [37] temperature and strain sensing, [38][39][40][41] and pulse amplification for Brillouin optical time-domain analysis (BOTDA). [42] The sensing applications of acoustic impedance include point-type [25][26][27][28][29] and distributed measurements. [30][31][32][33][34][35] Compared with pointtype sensors, a key advantage of distributed sensors lies in the multi-point simultaneous measurement.…”