Title :
High Spatial and Spectral Resolution Long-Range Sensing Using Brillouin Echoes
Author :
Foaleng, Stella M. ; Tur, Moshe ; Beugnot, Jean-Charles ; Thévenaz, Luc
Author_Institution :
Inst. of Electr. Eng., Ecole Polytech. Fed. de Lausanne, Lausanne, Switzerland
Abstract :
High spatial ( cm) and spectral ( MHz) resolution Brillouin sensing is realized with enhanced signal to noise ratio using a pre-activated acoustic field and an optical phase control over the interrogating pulse. Pre-activation of the acoustic field preserves the Brillouin natural linewidth and a differential gain technique extends the method to long ranges. Experimentally, fully resolved measurements of the Brillouin frequency shift of a 5 cm spot perturbation at the far end of a 5 km fiber have been performed with a frequency resolution of 3 MHz (2) , using a 500 ps (5 cm) phase shift pulse.
Keywords :
fibre optic sensors; spectral line breadth; stimulated Brillouin scattering; Brillouin echoes; Brillouin frequency shift; Brillouin natural linewidth; Brillouin sensing; differential gain technique; high spectral resolution long-range sensing; optical phase control; pre-activated acoustic field; signal-to-noise ratio; Acoustic waves; Optical fibers; Phonons; Scattering; Sensors; Spatial resolution; Brillouin echoes; distributed fiber sensor; fiber optics sensors; stimulated Brillouin scattering;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2010.2073443
