Distributed Brillouin Fiber Sensor With Enhanced Sensitivity Based on Anti-Stokes Single-Sideband Suppressed-Carrier Modulation

Abstract

Abstract-We demonstrate an alternative technique to reduce pump depletion and to improve sensitivity in long-range Brillouin optical time-domain analysis (BOTDA) sensor. Our BOTDA system uses an anti-Stokes single-sideband suppressed-carrier (SSB-SC) modulation technique that balances the pump depletion due to fiber loss. With this technique, we show both numerically and experimentally a great improvement compared to the dual sideband standard technique.Index Terms-Fiber optic sensor, Brillouin optical time domain analysis, single-sideband modulation.

Characterization of Stimulated Brillouin Scattering in Polymer Optical Fibers Based on Lock-in-Free Pump–Probe Technique

“…Thus, SBS can be induced at much lower pump power. This scheme has been exploited in developing silica SMF-based BOTDA [6], [18] and BOCDA systems [9], [19]. Although many researchers have attempted to induce SBS in POFs, hardly any experimental results have been reported thus far.…”

Brillouin Scattering in Optical Fibers and Its Application to Distributed Sensors

“…Most recently, specially-designed EDFA repeaters were used to extend the sensing measurements of BOTDA to more than 300 km [154]. Some efforts were also made to study the influence of Brillouin depletion on the maximum range of BOTDA [41] and to avoid it to some extent by use of Stokes together with anti-Stokes wave as Brillouin probe [155,156].…”

Capteur Brillouin réparti à fibre optique à haute résolution et longue portée

“…Dans cette section, nous présentons un capteur Brillouin réparti utilisant la modulation à bande latérale unique (BLU) anti-Stokes (Nguyen et al, 2013). Cette technique, basée sur la mesure des pertes anti-Stokes au lieu du gain Stokes, permet effectivement de compenser la déplétion de la pompe par transfert d'énergie de la bande latérale anti-Stokes et ainsi améliorer de façon significative la sensibilité du capteur.…”

“…Avec cette technique, une modulation de phase de π radians est obtenue par commutation positive/négative de la tension appliquée directement à un modulateur d'intensité autour de son point minimum, ce qui permet d'atteindre une résolution spatiale de 5 cm par la méthode différentielle des échos Brillouin . Le second système emploie un modulateur à deux interféromètres de MachZehnder parallèles de type I/Q (In-phase and Quadrature-phase) opérant dans un régime à bande latérale unique tout en supprimant efficacement la porteuse Nguyen et al, 2013 …”