Abstract

A distributed acoustic sensing system based on broadband weak fiber Bragg grating array which is capable of quantifying multiple dynamic strain perturbations is introduced. The technique is based on measuring the phase of the interference signals between two adjacent weak FBGs. Phase, amplitude, frequency response and location information can be directly obtained at the same time by using the passive 3×3 coupler demodulation technique. The experimental results show that this system can well demodulate vibration signals with different frequencies and amplitudes generated by piezoelectric transducer. Meanwhile, the system realized acoustic-phase detection in the air with a frequency range of 87Hz to 1250Hz.

© 2018 The Author(s)