Sub-metric spatial resolution over an extended range using differential time-domain Brillouin sensing

This paper reports on a distributed fiber sensing scheme to achieve sub-metric spatial resolution and long sensing ranges based on a differential pulse-width pair (DPP) Brillouin sensor. The scheme uses a scanning method in which the spectral separation between the two probe sidebands is kept constant, while the optical frequency of the pump is swept to scan the Brillouin spectral response. Experimental results show that the method avoids detrimental temporal distortions of the pulses, which in a standard implementation prevent the DPP method to operate over long distances. Here we demonstrate that this novel scanning method enables distributed sensing over 37.5 km with a spatial resolution of 20 cm and a frequency uncertainty of 1.9 MHz, obtained with 2k averages in a measurement time of a few minutes.

[1]  Luc Thévenaz,et al.  Going beyond 1000000 resolved points in a Brillouin distributed fiber sensor: theoretical analysis and experimental demonstration , 2016, Light: Science & Applications.

[2]  Luc Thévenaz,et al.  Effect of pulse depletion in a Brillouin optical time-domain analysis system. , 2013, Optics express.

[3]  Fabrizio Di Pasquale,et al.  Optimization of a Dpp-botda Sensor with 25 Cm Spatial Resolution over 60 Km Standard Single-mode Fiber Using Simplex Codes and Optical Pre-amplification References and Links High Spatial Resolution and Long-distance Botda Using Differential Brillouin Gain in A , 2022 .

[4]  A. Zadok,et al.  Random‐access distributed fiber sensing , 2012 .

[5]  Sonia Martin-Lopez,et al.  Non-local effects in dual-probe-sideband Brillouin optical time domain analysis. , 2015, Optics express.

[6]  Luc Thévenaz,et al.  Modeling and evaluating the performance of Brillouin distributed optical fiber sensors. , 2013, Optics express.

[7]  K. Shimizu,et al.  Development of a distributed sensing technique using Brillouin scattering , 1995 .

[8]  X. Bao,et al.  Differential pulse-width pair BOTDA for high spatial resolution sensing. , 2008, Optics express.

[9]  R. Bernini,et al.  A Simple Technique for Reducing Pump Depletion in Long-Range Distributed Brillouin Fiber Sensors , 2009, IEEE Sensors Journal.

[10]  Marcelo A. Soto,et al.  Reaching the ultimate performance limit given by non-local effects in BOTDA sensors , 2015, International Conference on Optical Fibre Sensors.

[11]  Kazuo Hotate,et al.  Measurement of Brillouin Gain Spectrum Distribution along an Optical Fiber Using a Correlation-Based Technique : Proposal, Experiment and Simulation (Special Issue on Optical Fiber Sensors) , 2000 .