Open AccessMultiple vibrations measurement using phase-sensitive OTDR merged with Mach-Zehnder interferometer based on frequency division multiplexing
Author(s) -
Haijie He,
Liyang Shao,
Bin Luo,
Zonglei Li,
Xihua Zou,
Zhiyong Zhang,
Wei Pan,
Lianshan Yan
Publication year - 2016
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.24.004842
Subject(s) - optical time domain reflectometer , optics , interferometry , reflectometry , physics , vibration , mach–zehnder interferometer , interference (communication) , frequency division multiplexing , frequency domain , multiplexing , optical fiber , fiber optic sensor , acoustics , time domain , orthogonal frequency division multiplexing , telecommunications , polarization maintaining optical fiber , computer science , channel (broadcasting) , computer vision
A novel measurement scheme for multiple high-frequency vibrations has been demonstrated by combining phase-sensitive optical time domain reflectometry (Ф-OTDR) and Mach-Zehnder interferometer (MZI) based on frequency division multiplexing. The light source is directly launched into the MZI structure, while it was modulated by an acoustic optical modulator (AOM) with a frequency shift of 200 MHz for the Ф-OTDR part. The vibration frequency is obtained by demodulating the interference signal obtained by the MZI structure, while the vibration position is located by Ф-OTDR system. The spatial resolution of 10m is obtained over 3 km sensing fiber. And the detectable vibration frequency reaches up to 40 kHz. Compared to the previous schemes, this system works without dead zone in the detectable frequency range. Furthermore, the frequency spectrum mapping method has been adopted to determine multiple high-frequency vibrations simultaneously. The experimental results prove the concept and match well with the theoretical analysis.