Optimization of long-range BOTDA sensors with high resolution using first-order bi-directional Raman amplification

Marcelo A Soto,Fabrizio Di Pasquale,Gabriele Bolognini

doi:10.1364/oe.19.004444

Abstract

In this paper we perform an optimization of Brillouin optical time-domain analysis (BOTDA) sensors for achieving high resolution over long sensing ranges using distributed Raman amplification. By employing an optimized first-order bi-directional Raman amplification scheme and combining high-power fiber-Raman lasers and Fabry-Pérot lasers with low relative-intensity-noise (RIN), we demonstrate distributed sensing over 120 km of standard single-mode fiber with 2 meter spatial resolution and with a strain/temperature accuracy of 45με/2.1°C respectively.

Highlights

Distributed optical fiber sensors technology is attracting a growing interest thanks to its wide range of potential industrial applications in strategic sectors such as energy, security, defense and transportation, among others
In this paper we analyze the impact of distributed Raman amplification, performing a careful optimization which is crucial for a significant sensing range enhancement, allowing one to fully exploit the Raman amplification benefits and minimize at the same time the potential penalties coming from several sources of noise
The frequency components of the Brillouin gain spectrum (BGS) of the sensing fiber have been scanned by sweeping the frequency difference between the Brillouin pump and probe signal [1]

Summary

Introduction

Distributed optical fiber sensors technology is attracting a growing interest thanks to its wide range of potential industrial applications in strategic sectors such as energy, security, defense and transportation, among others. In this paper we analyze the impact of distributed Raman amplification, performing a careful optimization (employing both numerical models and experiments) which is crucial for a significant sensing range enhancement, allowing one to fully exploit the Raman amplification benefits and minimize at the same time the potential penalties coming from several sources of noise. Distributed Raman amplification can be used for enhancing the performance of distributed fiber sensors based on stimulated or spontaneous Brillouin scattering [3,4,5,6], a great care must be taken in their practical implementation. In order to fully exploit the Raman amplification benefit, it is necessary to minimize such arising penalties by employing suitable techniques and devising effective solutions

Methods

Results

Conclusion