Urricelqui Polvorinos, JavierSagüés García, MikelLoayssa Lara, Alayn2016-11-152016-11-1520141094-408710.1364/OE.22.017403https://academica-e.unavarra.es/handle/2454/22700We introduce a novel phasorial differential pulse width pair (PDPP) method for Brillouin optical time domain analysis (BOTDA) sensors that combines spatial resolution enhancement with increased tolerance to non local effects. It is based on the subtraction of the complex time domain traces supplied by a sensor configuration that uses a phase modulated probe wave and RF demodulation. The fundamentals of the technique are first described theoretically and using numerical simulation of the propagating waves. Then, proof of concept experiments demonstrate the measurement of the Brillouin frequency shift distribution over 50 km. The system is shown to withstand large variations of the pump power generated by its interaction with a powerful probe wave along the fiber; hence, highlighting the potential of the PDPP technique to increase the detected signal to noise ratio in long range BOTDA. Moreover, the PDPP is also shown to increase the measurement contrast by allowing the use of relatively long duration pulses while retaining 1 m spatial resolution.application/pdfeng© 2014 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.Stimulated Brillouin scatteringFiber optics sensorsHeterodyneBrillouin optical time domain analysisinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess