Open AccessPhase-detection distributed fiber-optic vibration sensor without fading-noise based on time-gated digital OFDR
Author(s) -
Dian Chen,
Qingwen Liu,
Zuyuan He
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.008315
Subject(s) - optics , fading , phase noise , vibration , optical fiber , distributed acoustic sensing , fiber optic sensor , acoustics , noise (video) , phase (matter) , bandwidth (computing) , physics , materials science , telecommunications , computer science , decoding methods , quantum mechanics , artificial intelligence , image (mathematics)
For a distributed fiber-optic vibration sensor (DFVS), the vibration signal extracted from the phase of backscattering has a linear response to the applied vibration, and is more attractive than that from the intensity term. However, the large phase noise at a random weak-fading-point seriously limits the sensor's credibility. In this paper, a novel phase-detection DFVS is developed, which effectively eliminates the weak-fading-point. The relationship between phase noise and the intensity of backscattering is analyzed, and the inner-pulse frequency-division method and rotated-vector-sum method are introduced to effectively suppress phase noise. In experiments, two simultaneous vibrations along the 35-kilometer-long fiber are clearly detected by phase detection with the signal-to-noise ratio (SNR) over 26 dB. The spatial resolution approaches 5 m and the vibration response bandwidth is 1.25 kHz.