Zhang Li, Yang Zhisheng, Gorbatov Nachum, Davidi Roy, Galal Malak, Thévenaz Luc, Tur Moshe
Opt Lett. 2020 Sep 15;45(18):5020-5023. doi: 10.1364/OL.395922.
A distributed and dynamic strain sensing system based on frequency-scanning phase-sensitive optical time domain reflectometry is proposed and demonstrated. By utilizing an RF pulse scheme with a fast arbitrary waveform generator, a train of optical pulses covering a large range of different optical frequencies, short pulse width, and high extinction ratio is generated. Also, a Rayleigh-enhanced fiber is used to eliminate the need for averaging, allowing single-shot operation. Using direct detection and harnessing a dedicated least mean square algorithm, the method exhibits a record high spatial resolution of 20 cm, concurrently with a large measurable strain range (80µε, 60 demonstrated), a fast sampling rate of 27.8 kHz (almost the maximum possible for a 55 m long fiber and 60 frequency steps), and low strain noise floor (<1.8ε/ for vibrations below 700 Hz and <0.7ε/ for higher frequencies).
提出并演示了一种基于频率扫描相敏光时域反射仪的分布式动态应变传感系统。通过利用快速任意波形发生器的射频脉冲方案，产生了一系列覆盖大范围不同光频率、短脉冲宽度和高消光比的光脉冲。此外，使用瑞利增强光纤消除了平均的需要，实现了单次测量操作。该方法采用直接检测并利用专用的最小均方算法，展现出创纪录的20 cm高空间分辨率，同时具有较大的可测量应变范围（已证明为80µε，60）、27.8 kHz的快速采样率（对于55 m长的光纤和60个频率步长几乎是最大可能值）以及低应变本底噪声（低于700 Hz的振动时<1.8ε/，更高频率时<0.7ε/）。
