多波长BOTDR系统中布里渊散射谱的特征提取  

Features extraction of Brillouin scattering spectra in multi-wavelength BOTDR system

作　　者：李晓娟[1] 李永倩[1] 胡智奇[1] 安琪[1] 

机构地区：[1]华北电力大学电子与通信工程系,河北保定071003

出　　处：《光电子．激光》2016年第12期1286-1292,共7页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61377088);河北省自然科学基金(F2014502098;F2015502059);中央高校基本科研业务费专项资金(2014XS77)资助项目

摘　　要：根据布里渊散射谱的传输特性和高精度特征提取的要求,理论分析了布里渊频移的波长依赖性和多波长探测光传感时的外差检测布里渊散射谱特征,提出了利用Pseudo-Voigt基函数和莱文伯格-马夸尔特(L-M)优化算法对布里渊散射叠加谱进行特征提取。通过与洛伦兹、高斯和5次多项式曲线拟合法进行预测比较,在中心频移为11.122 903GHz的单波长和多波长传感的仿真散射谱模型中,本文所提方法的频移测量误差最小,对应的温度测量误差仅为0.047、0.000和0.112℃,且拟合度最好。在采用多模法布里-珀罗激光器的布里渊散射谱检测系统中,Pseudo-Voigt曲线拟合的综合评价指标优于其他3种拟合方法。仿真分析和实验结果表明,Pseudo-Voigt曲线拟合适用于多波长传感时布里渊散射叠加谱的特征提取,可有效地提高预测精度。Considering the characteristics of the spectral shape variance during the Brillouin scattering process in optical fiber and the requirement of feature extraction at high accur acy,the wavelength dependence of Brillouin frequency shift and the characteristics of heterodyne de tection Brillouin scattering spectra for multi-wavelength probe light sensing are analyzed theor etically,and a method to extract features of superposed Brillouin scattering spectra based on Pseudo-Vo igt basis function and Levenberg-Marquard optimized algorithm is presented.A model of actual Brilloui n spectra is constructed by Gaussian white noise in the theoretical spectra for single-wavelength and mu lti-wavelength probe lights sensing,and the center frequency shift is 11.122903GH z.Compared with the Lorentzian, Gaussian and fifth-order polynomial curve fitting methods,the measurement erro rs of Brillouin frequency shift with Pseudo-Voigt curve fitting are the smallest,and the corre sponding measurement errors of temperature are 0.047 ℃,0℃ and 0.112℃.The evaluation parameters ar e better than those of other three curve fitting methods in the same test system. The simulation and experiment results show that the Pseudo-Voigt curve fitting is suitable for the features extraction of superpose d Brillouin spectra for multi-wavelength probe light sensing,and the prediction accuracy is improved efficiently.

关 键 词：布里渊光时域反射(BOTDR) 布里渊散射叠加谱 莱文伯格-马夸尔特(L -M)算法 Pseudo-Voigt基函数 

分 类 号：TN247[电子电信—物理电子学]