Abstract

We demonstrate simultaneous strain and temperature sensing based on hybrid Raman and Brillouin scattering with enhanced performance thanks to the combined use of standard Fabry-Perot lasers in conjunction with optical pulse coding techniques. The combination of both techniques allows for an improvement of similar to 8.7 dB in temperature resolution and similar to 3 dB in strain resolution, with respect to standard distributed feedback lasers, as confirmed by experiments, resulting in a final temperature / strain resolution of similar to 0.27K / similar to 30 mu epsilon over 25-km sensing fiber range, avoiding the use of optical amplification and wavelength averaging techniques. (C) 2010 Optical Society of America