A highly sensitive OFDR system capable of detecting and tracking fast acoustic wave propagation is described. The system was tested by dropping a screw (50gr) and a paperclip (<5gr) at one end of an 18m PVC pipe. The sensing fiber detected the wave propagation (v ≈ 1750m/s) along the entire pipe. Fast phase variations due to the impact of the screw led to a transient shift in the frequency of the interrogating light which corrupted the observed response. By tracking the beat frequencies of predefined reflectors and extracting their amplitudes significant improvement in the system's output was obtained.

Date Published: 2 June 2014
PDF: 4 pages
Proc. SPIE 9157, 23rd International Conference on Optical Fibre Sensors, 91576R (2 June 2014); doi: 10.1117/12.2059601

Published in SPIE Proceedings Vol. 9157:
23rd International Conference on Optical Fibre Sensors
José M. López-Higuera; Julian D. C. Jones; Manuel López-Amo; José Luis Santos, Editor(s)