瑞利BOTDA传感系统EOM最佳化设计及实验研究

发布时间：2018-03-27 21:42

  本文选题：分布式光纤传感　切入点：BOTDA系统　出处：《华北电力大学》2016年硕士论文

【摘要】：本文综述了分布式光纤传感技术近年来研究方向,并详细论述了瑞利布里渊光时域分析(R-BOTDA)系统国内外发展研究现状。理论上详细研究了BOTDA系统的技术原理;分析了受激布里渊散射(SBS)稳态耦合波方程和瞬态耦合波方程,以及布里渊频移与光纤温度、应变的关系。针对BOTDA系统受非本地效应影响,分析研究了泵浦光能量损耗和光纤长度、探测光功率之间的关系,定量分析了光纤长度、探测光功率和BOTDA系统中非本地效应引起的测量误差之间的关系。对SMF光纤的仿真研究表明:当光纤长度为2000m时,非本地效应会引起1.5℃的温度误差、30με的应变误差。为改善BOTDA系统中非本地效应对系统的影响,本文构建了一种脉冲预泵浦瑞利BOTDA系统(PPP-RBOTDA),运用预泵浦脉冲1阶边带激发的瑞利散射光做探测光,使得瑞利散射光分别与预泵浦脉冲的0阶基带和传感脉冲发生受激布里渊作用,通过检测散射回来的瑞利光信号获取光纤的温度和应变信息。建立了瞬态条件下脉冲预泵浦和传感脉冲发生SBS作用的数学模型,对阶梯脉冲进行了最佳化设计,运用Matlab软件仿真研究表明当传感脉冲为50mw、6ns,预泵浦脉冲为500mW、100ns时,可获得满足PPP-RBOTDA系统要求的瑞利散射光,且瑞利散射光发生SBS作用产生的FWHM为布里渊自然增益线宽34MHz,能有效减小瞬态SBS作用下FWHM的展宽效应,提高系统的频谱分辨率。探讨了EOM用于PPP-RBOTDA系统时的最佳工作点问题;运用Opti System软件进行仿真研究,验证了EOM调制产生的预泵浦信号含有0阶基带和1阶边带信号。搭建了实验系统,合成了阶梯脉冲;通过对EOM射频端进行扫频操作,对瑞利散射信号进行采集处理后,成功拟合出了布里渊损耗谱曲线。
[Abstract]:In this paper, the research direction of distributed optical fiber sensing technology in recent years is reviewed, and the research status of Rayleigh Brillouin optical time domain analysis (R-BOTDA) system at home and abroad is discussed in detail. The technical principle of BOTDA system is studied in theory. The steady-state coupled wave equation and transient coupled wave equation of stimulated Brillouin scattering (SBS), and the relationship between Brillouin frequency shift and fiber temperature and strain are analyzed. The relationship between the energy loss of pump light and the length of the fiber and the power of the probe light is analyzed and the length of the optical fiber is quantitatively analyzed. The relationship between the detecting optical power and the measurement error caused by the non-native effect in the BOTDA system. The simulation results of the SMF fiber show that when the length of the fiber is 2000m, In order to improve the influence of non-native effect on BOTDA system, the temperature error of 1.5 鈩，

本文编号：1673334