Distributed optical fiber vibration sensors based on unbalanced Michelson interferometer and PGC demodulation

Abstract

In this paper, we propose a distributed optical fiber vibration sensing system based on Φ-OTDR and Michelson interferometer. It can detect multiple vibrations simultaneously along a sensing fiber, and the vibration waveform, frequency, position and amplitude could be demodulated correctly using our proposed PGC demodulation algorithm. The experimental results show, a SNR of 34.86 dB is achieved with the background noise level of − 37 dB at the 1000 m, and the SNR is 28.09 dB with the background noise level of − 32 dB at the 6000 m.