Self-Mixing Demodulation for Coherent Phase-Sensitive OTDR System

被引：35

作者：

He, Haijun ^{[1
]}

Shao, Li-Yang ^{[1
]}

Li, Zonglei ^{[1
]}

Zhang, Zhiyong ^{[1
]}

Zou, Xihua ^{[1
]}

Luo, Bin ^{[1
]}

Pan, Wei ^{[1
]}

Yan, Lianshan ^{[1
]}

机构：

[1] Southwest Jiaotong Univ, Sch Informat Sci & Technol, Ctr Informat Photon & Commun, Chengdu 610031, Peoples R China

来源：

SENSORS | 2016年 / 16卷 / 05期

基金：

中国国家自然科学基金;

关键词：

fiber optics sensors; remote sensing and sensors; scattering measurement; optical time domain reflectometry; TIME-DOMAIN REFLECTOMETRY; PHI-OTDR;

D O I：

10.3390/s16050681

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

Phase-sensitive optical time domain reflectometry (Phi-OTDR) attracts much attention due to its capability of telling the type and position of an intrusion simultaneously. In recent decades, coherent Phi-OTDR has been demonstrated to realize long-distance detection. For coherent Phi-OTDR, there are three typical demodulation schemes in the reported studies. However, they still cannot realize real-time monitoring to satisfy practical demands. A simple and effective demodulation method based on self-mixing has been put forward to demodulate the beat signal in coherent Phi-OTDR. It not only saves a local electrical oscillator and frequency locked loop, but also demodulates the beat signal without residual frequency. Several vibrations with different frequency were separately applied at the same location of a 42.5 km fiber. The spatial resolution of 10 m and frequency response range from 8 Hz to 980 Hz have been achieved. The precise location with signal-to-noise ratio of 21.4 dB and broadband measurement demonstrate the self-mixing scheme can demodulate the coherent Phi-OTDR signal effectively.

引用

页数：10

共 23 条

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