分布式布里渊光纤应变传感信号的增敏检测方法

发布时间：2018-06-24 14:01

本文选题：增敏检测 + 光纤传感　；参考：《光电子.激光》2014年05期

【摘要】：基于外差相干检测原理,摒弃了传统扫频构建布里渊散射频谱的方法,以布里渊散射光功率为应变监测参量,利用具有增敏作用的高频脉冲检波管对布里渊散射拍频信号进行包络检波,直接将拍频信号转换成布里渊散射功率信号,并对携带应变信息的布里渊散射功率信号进行应变增敏检测,利用高频脉冲检波管增益响应曲线对功率信号的调制提高散射功率应变敏感系数。经测试,增敏后布里渊散射光功率应变敏感系数为0.024%/με,与传统直接检测法得到的应变敏感系数-7.7×10-4%/με相比,敏感系数提高30倍,有效提高了系统信噪比;对增敏后的布里渊功率信号进行解调,在24.7km的光纤长度上,实现65με的应变测量标准差,测量时间由传统扫频方法的超过30s降为仅1s。本文系统可有效满足快速精确检测应变的监测需求,且不需要扫频模块等复杂器件,结构简单,稳定性高,对实际应用具有重要的意义。
[Abstract]:Based on the principle of heterodyne coherence detection, the method of constructing Brillouin scattering spectrum is abandoned, and Brillouin scattering light power is used as the strain monitoring parameter. The Brillouin scattering beat signal is detected by an enhanced high frequency pulse detector, and the beat frequency signal is converted directly into the Brillouin scattering power signal. The strain sensitizing detection of Brillouin scattering power signal with strain information is carried out, and the modulation of power signal by gain response curve of high frequency pulse detector tube is used to improve the strain sensitivity coefficient of scattering power. The strain sensitivity coefficient of Brillouin scattering light is 0.024 / 渭蔚, which is 30 times higher than the strain sensitivity coefficient -7.7 脳 10 ~ (-4) / 渭蔚 of the conventional direct detection method, and the signal-to-noise ratio of the system is improved effectively. Based on the demodulation of Brillouin power signal, the strain measurement standard deviation of 65 渭蔚 is realized in the fiber length of 24.7km. The measuring time is reduced from 30 s to 1 s. This system can effectively meet the need of rapid and accurate strain monitoring, and does not need complex devices such as frequency sweep module. The system has simple structure and high stability, which is of great significance for practical application.
【作者单位】：闽南师范大学物理与信息工程学院;
【基金】：福建省教育厅基金(JB12143) 2012闽南师范大学校杰青计划(SJ12001)资助项目
【分类号】：TN911.23

【参考文献】