布里渊传感中高精度测量的布里渊谱去卷积法

Brillouin Spectral Deconvolution Method for High Accuracy Measurement in Brillouin Sensors

在泵浦探测型布里渊分布式传感器中,结合直流和短脉冲(1 ns)激光作为探测光,可用底部为高斯型和顶部为洛伦兹型的双重结构来描述布里渊光谱。由于两者的相互作用,利用从洛伦兹型部分提取厘米级分辨率的空间信息改进了一种光谱去卷积方法,考虑应变区域相关性,在洛伦兹型部分确定布里渊谱峰的数量和频率,从而获得精确应变信息。最后,对最优直流电压进行了探讨。

Combining DC and short pulse （Ins） as the probe beam in the pump-probe configuration of Brillouin-based distributed sensors allows us to represent the Brillouin spectrum as bottom Gaussian-like portion and top Lorentzian-like portion. Because of the interaction of these two parts, the Lorentzian-like portion carries spatial information that can be extracted within centimeter spatial resolution. Using this information, we developed spectrum deconvolution method, which considered the location correlation of the strain distribution, to find the number of Brillouin peaks and their frequencies in the top Lorentzian-like portion and hence achieve accurate strain information. An optimum level of DC to pulse power for the best signal and position detection capability was discussed.