Simplex-coded BOTDA fiber sensor with 1 m spatial resolution over a 50 km range

In this Letter, we propose the use of optical pulse coding techniques for long-range distributed sensors based on Brillouin optical time-domain analysis (BOTDA). Compared to conventional BOTDA sensors, optical coding provides a significant sensing-range enhancement, allowing for temperature and strain measurements with1mspatialresolution over 50 km of standard single-mode fiber, with an accuracy of 2.2°C/44 ??, respectively. © 2010 Optical Society of America.