Differential Pulse-Width Pair Brillouin Optical Time-Domain Analysis Employing Raman Amplification and Optical Pulse Coding

We report on an advanced optical fiber sensing implementation enabling submeter resolution over long distance exploiting Brillouin optical time-domain analysis with differential pulse-width pair. Long sensing distances have been attained thanks to the combined use of distributed Raman amplification of optical signals together with optical pulse coding. We experimentally demonstrate strain–temperature sensing capabilities with a spatial resolution better than 50 cm throughout 93 km standard single-mode fiber, attaining accuracy in terms of measured strain and temperature smaller than 1.7 °C and 34 με, respectively.