%0 Journal Article 
%A Fidalgo Martins, Hugo
%A Martín López, Sonia
%A Corredera, Pedro
%A Ania Castañón, Juan Diego
%A Frazão, O.
%A González Herráez, Miguel
%T Distributed vibration sensing over 125 km with enhanced SNR using ΦOTDR over a URFL cavity
%D 2015
%@ 0733-8724
%U http://hdl.handle.net/10017/26309
%X We describe the use of a phase-sensitive optical time domain reflectometer (ΦOTDR) over an ultra-long Raman fiber laser cavity allowing fully distributed detection of vibrations over 125 km. Compared to a first-order Raman-assisted ΦOTDR, this scheme shows an enhanced signal-to-noise ratio (SNR). This is due to the fact that the relative intensity noise introduced by the Raman amplification is mostly transferred to a lower frequency range, where the balanced detection implemented in the setup provides better suppression of the common-mode noise. The sensor was able to measure vibrations of up to 380 Hz (limit set by the time of flight of light pulses) in a distance of 125 km with a resolution of 10 m and an average SNR of 8 dB with no postprocessing. This implies a >3 dB improvement in SNR over a first-order Raman-assisted setup with similar characteristics
%K Distributed sensor
%K Optical fiber sensors
%K Phase sensitive OTDR
%K Raman scattering
%K Vibration sensor
%K Electrónica
%K Electronics
%~ Biblioteca Universidad de Alcala