Open AccessFiber-optic distributed acoustic sensor utilizing LiNbO3 straight through waveguide phase modulator
Author(s) -
Fai Ma,
Ningfang Song,
Xiaxiao Wang,
Peng Wang,
Haoyu Ma,
Yizhen Wang,
Peng Xiao,
Jia Yu
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.424010
Subject(s) - demodulation , optics , phase modulation , distributed acoustic sensing , modulation (music) , fiber optic sensor , optical fiber , signal (programming language) , optical time domain reflectometer , homodyne detection , noise (video) , frequency modulation , materials science , phase (matter) , acoustics , phase noise , physics , fiber optic splitter , telecommunications , radio frequency , computer science , channel (broadcasting) , quantum mechanics , artificial intelligence , image (mathematics) , programming language
A novel fiber-optic distributed acoustic sensor (DAS) utilizing a LiNbO 3 straight through waveguide phase modulator as phase generation carrier (PGC) modulation module for the detection of acoustic signal is presented. The sensitive principle and the phase demodulation method of the system based on phase-sensitive optical time domain reflectometer (Φ-OTDR) are described. This scheme solves the problems of low modulation frequency and unstable performance of piezoelectric transducer (PZT) in the traditional homodyne detection system and depends only on the pulse repetition frequency. The efficacy of the new approach is demonstrated experimentally, showing that the weak acoustic signal can be demodulated accurately. The noise level of the system is < 4.2×10 -3 rad/√Hz, the signal to noise ratio (SNR) is > 16 dB, and the spatial resolution is 10 m, as well as a detection frequency can theoretically achieve 25 kHz at 2 km sensing fiber. It provides a new research idea for DAS and is expected to replace PZT to achieve a high-frequency response, which has good potential in the applications of low cost, long distance and high frequency detection.