Zhang Jingdong, Zhu Tao, Zhou Huan, Huang Shihong, Liu Min, Huang Wei
Opt Express. 2016 Nov 28;24(24):27482-27493. doi: 10.1364/OE.24.027482.
We demonstrate a cost-effective distributed fiber sensing system for the multi-parameter detection of the vibration, the temperature, and the strain by integrating phase-sensitive optical time domain reflectometry (φ-OTDR) and Brillouin optical time domain reflectometry (B-OTDR). Taking advantage of the fast changing property of the vibration and the static properties of the temperature and the strain, both the width and intensity of the laser pulses are modulated and injected into the single-mode sensing fiber proportionally, so that three concerned parameters can be extracted simultaneously by only one photo-detector and one data acquisition channel. A data processing method based on Gaussian window short time Fourier transform (G-STFT) is capable of achieving high spatial resolution in B-OTDR. The experimental results show that up to 4.8kHz vibration sensing with 3m spatial resolution at 10km standard single-mode fiber can be realized, as well as the distributed temperature and stress profiles along the same fiber with 80cm spatial resolution.
我们展示了一种经济高效的分布式光纤传感系统，通过集成相敏光时域反射仪（φ-OTDR）和布里渊光时域反射仪（B-OTDR），实现对振动、温度和应变的多参数检测。利用振动的快速变化特性以及温度和应变的静态特性，对激光脉冲的宽度和强度进行调制，并按比例注入单模传感光纤，从而仅通过一个光电探测器和一个数据采集通道就能同时提取三个相关参数。一种基于高斯窗短时傅里叶变换（G-STFT）的数据处理方法能够在B-OTDR中实现高空间分辨率。实验结果表明，在10km标准单模光纤上，可实现高达4.8kHz的振动传感，空间分辨率为3m，同时还能实现沿同一光纤的分布式温度和应力分布，空间分辨率为80cm。
