利用局部受激散射激励提升紧凑型低成本BOTDR系统探测精度  

Detection Accuracy Improvement of Compact and Low-Cost BOTDR System Using Locally Stimulated Scattering Excitation

作　　者：刘鑫煜 陈理平 陈玉明[4] 李拥政 黄秋茗 陈映恺 郭林峰 徐小敏 Liu Xinyu;Chen Liping;Chen Yuming;Li Yongzheng;Huang Qiuming;Chen Yingkai;Guo Linfeng;Xu Xiaomin(School of Physics and Optoelectronic Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Jiangsu Key Laboratory for Optoelectronic Detection of Atmosphere and Ocean,Nanjing 210044,Jiangsu,China;China Railway(Shanghai)Investment Group Co.,Ltd.,Shanghai 200126,China;Jiangsu Product Quality Testing&Inspection Institute,Nanjing 210007,Jiangsu,China;China Railway No.3 Group East China Construction Co.,Ltd.,Nanjing 211153,Jiangsu,China;Jiangsu International Joint Laboratory on Meterological Photonics and Optoelectronic Detection,Nanjing 210044,Jiangsu,China;Department of Engineering,University of Cambridge,Cambridge CB21PZ,United Kingdom)

机构地区：[1]南京信息工程大学物理与光电工程学院,江苏南京210044 [2]江苏省大气海洋光电探测重点实验室,江苏南京210044 [3]中铁(上海)投资集团有限公司,上海200126 [4]江苏省产品质量监督检验研究院,江苏南京210007 [5]中铁三局集团华东建设有限公司,江苏南京211153 [6]江苏省气象光子学与光电探测国际合作联合实验室,江苏南京210044 [7]剑桥大学工程系,英国剑桥CB21PZ

出　　处：《光学学报》2024年第11期40-49,共10页Acta Optica Sinica

基　　金：国家自然科学基金(62175113);江苏省重点研发计划(BE2022076)。

摘　　要：提出一种利用局部受激布里渊散射(SBS)提升布里渊光时域反射(BOTDR)系统的检测精度的方法。实验中使用20 ns的泵浦脉冲,设置脉冲频率为40 kHz,在23℃温度下对1009 m待测光纤进行测量,然后设置脉冲频率为20 kHz,对2019 m待测光纤进行测量,比较不同电流下频移分布的均方根误差(RMSE)。使用50 ns的泵浦脉冲,设置脉冲频率为20 kHz,对2000 m待测光纤上前端和后端各50 m长度光纤水浴加热至50℃并进行测量。实验结果说明尽管发生的SBS会减小BOTDR系统的传感距离,但却能够在一定程度上提高温度/应变的探测精度。与传统BOTDR系统相比,所提系统利用局部SBS提高了BOTDR系统特定距离上的探测精度,使得紧凑型低成本BOTDR系统的工程实用性得以提高。Objective The distributed Brillouin optical time domain reflectometry(BOTDR)sensing system is based on the linear relationship between the frequency shift of spontaneous Brillouin scattering(SpBS)and temperature/strain on the optical fiber.It utilizes a convenient structure of single-ended incident light detection to measure temperature and strain along the fiber over long distances,reducing measurement complexity and application costs.Meanwhile,it allows for continued fiber detection even when the optical fiber is broken on an engineering construction site,avoiding the limitations associated with employing a double-ended loop Brillouin optical time domain analysis(BOTDA)sensing system after the fiber loop breakage.This makes the BOTDR system more practical in engineering applications.However,due to limitations imposed by stimulated Brillouin scattering(SBS),if only SpBS occurs in the system,the power can not exceed SBS’s threshold power.Consequently,the low incoming fiber optical power results in weak signal energy and a low signal-to-noise ratio(SNR)within the system,affecting overall detection accuracy.To improve the SNR without increasing complexity or detection costs,we propose a method that enhances the compactness and affordability of BOTDR systems by local stimulated scattering excitation.Methods To validate the method’s feasibility,we conduct three experiments.Firstly,a 20 ns pump pulse is utilized at room temperature with a pulse frequency of 40 kHz to measure the 1009 m optical fiber under test.By comparing the root mean square error(RMSE)of the frequency shift distribution at different positions and various current levels,it is confirmed that increasing the operating current of EDFA can enhance the SNR of the BOTDR system in the absence of SBS occurrence.Subsequently,by setting the pulse cycle frequency to 10 kHz,we measure a 2019 m optical fiber under test.The RMSE of the optical fiber’s frequency shift distribution is calculated in segments.Comparison between eight segments with different curr

关 键 词：光通信 布里渊光时域反射 自发布里渊散射 受激布里渊散射 检测精度 

分 类 号：O436[机械工程—光学工程]