Opt Lett. 2018 Nov 15;43(22):5607-5610. doi: 10.1364/OL.43.005607.
We introduce a simple method to extend the performance of pulse coding techniques in their application to Brillouin optical time-domain analysis sensors (BOTDA). It is based on applying a simple logarithmic processing on the detected probe wave that compensates the deviation from linearity of the sensor response for long code lengths. The technique ensures that the accumulated effect of a sequence of pulses is equal to the linear addition of the effects of the individual components, which is the essential condition to ensure a correct decoding of the probe gain measurement. We experimentally demonstrate the compensation of the Brillouin frequency shift error induced by the accumulated gain nonlinearity. Furthermore, a proof-of-concept 80 km sensing link within a total 200 km fiber loop demonstrated a better than 2 MHz precision with 2 m spatial resolution.
我们提出了一种简单的方法来扩展脉冲编码技术在布里渊光时域分析传感器（BOTDA）中的应用性能。该方法基于对探测波进行简单的对数处理，补偿了长码长下传感器响应的非线性偏差。该技术确保了一系列脉冲的累积效应等于单个分量的效应的线性叠加，这是确保正确解码探测增益测量的必要条件。我们实验证明了对由累积增益非线性引起的布里渊频移误差的补偿。此外，在总长度为 200km 的光纤环内进行的 80km 传感链路的概念验证实验表明，该技术具有优于 2MHz 的精度和 2m 的空间分辨率。
