Guo Nan, Wang Liang, Wang Jie, Jin Chao, Tam Hwa-Yaw, Zhang A Ping, Lu Chao
Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Sensors (Basel). 2016 Dec 16;16(12):2156. doi: 10.3390/s16122156.
We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes.
我们提出并通过实验证明了一种用于扩展传感范围的新型双向布里渊时域分析仪（BD-BOTDA）方案。通过在两个不同波长处部署两对泵浦-探测光，在同时检测两个通道中的布里渊信号时，可以获得整个光纤每半段上的布里渊频移（BFS）分布。与具有相同传感范围的传统单向BOTDA系统相比，所提出的BD-BOTDA方案能够实现分布式传感，其性能水平与传感范围减半且空间分辨率为2 m的传统系统相当，同时保持布里渊信噪比（SNR）和BFS不确定度。基于该技术，我们在不引入任何复杂组件或方案的情况下，实现了空间分辨率为2 m、BFS不确定度约为0.44 MHz、测量范围达81.9 km光纤的分布式温度传感。
