基于开放光路离轴积分腔的甲烷传感技术与实验  

Open-Path Off-Axis Integrated Cavity-Based Methane Sensing Technique and Experiment

作　　者：李俊豪 郑凯元 席振海 刘梓迪 郑传涛[1,2] 王一丁 Li Junhao;Zheng Kaiyuan;Xi Zhenhai;Liu Zidi;Zheng Chuantao;Wang Yiding(State Key Laboratory of Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun,Jilin 130012,China;Jilin Provincial Engineering Research Center of Infrared Gas Sensing Technique,Changchun,Jilin 130012,China)

机构地区：[1]吉林大学集成光电子学国家重点联合实验室,电子科学与工程学院,吉林长春130012 [2]吉林省红外气体传感技术工程研究中心,吉林长春130012

出　　处：《中国激光》2021年第16期144-152,共9页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFB0405300);国家自然科学基金(61775079,61627823,61960206004);吉林省科技发展计划(20180201046GX,20190101016JH,20200401059GX)。

摘　　要：为了实现大气甲烷(CH4)浓度的高灵敏、实时检测,研制了一种基于开放光路的高稳定性笼式结构光学谐振腔,并结合离轴积分腔输出光谱技术研制了一种大气CH4浓度传感系统。采用中心波长为1653 nm的可调谐半导体激光器作为光源,将反射率为99.92%的高反射镜置于距离光源35 cm处构建光学谐振腔。实验测得高反射镜的实际反射率为99.93%,谐振腔的有效光程可达516 m。Allan方差结果表明,当积分时间为4 s时,基于离轴积分腔的CH4检测系统的最低检测下限为8×10^(-9)。利用开放光路的优势,开展了CH4泄漏模拟实验,实验证明该系统具有快速检测CH4泄漏的能力,为进一步研制应用于现场、且能快速响应的甲烷泄漏检测仪提供了依据。Objective Methane(CH4)is the main component of natural gas;it is a kind of colorless,odorless,flammable,and explosive gas.It has major safety hazards in natural gas transportation and coal mining.The demand for natural gas has gradually increased recently.Generally,natural gas is transported to various areas through pipelines,and the aging of pipelines may cause leakages,which will cause long-term CH4emissions,resulting in severe environmental problems and huge energy waste.In a closed environment,CH4leakage is difficult to detect,which leads to potential hazards,such as suffocation and explosion.For example,in factories,coal mines,and other places,when the CH4concentration in the environment reaches a certain limit (5%--17%),an explosion will occur,leading to severe safety accidents.Therefore,real-time and accurate CH4concentration detection in the production environment is paramount to ensure life safety and reduce economic losses.In this study,a near-infrared sensor system based on the open-path off-axis integrated cavity output spectroscopy (OA-ICOS)technique was proposed for fast and real-time atmospheric CH4 concentration detection.Further,simulated CH4leakage detection and the performance of the sensor system were verified through gas sensing experiments.Methods CH4 detection methods include catalyst combustion,electrochemistry,and infrared laser absorption spectroscopy.Infrared laser absorption spectroscopy is widely used because of its in situquantification.OA-ICOS is a type of laser absorption spectroscopy and has received enormous attention recently due to its long optical path(OP),high robustness,and other advantages.In this experiment,the OA-ICOS technique was used to detect CH4in real time based on an open OP design.A tunable semiconductor laser with a center wavelength of 1653 nm was used as the light source,and a highly stable optical cavity with a cage structure was fabricated with two high reflectance mirrors of 99.92%apart 35cm.The optimal position of the off-axis integrated cavity output signa

关 键 词：传感器 离轴积分腔输出光谱 开放光路 天然气泄漏检测 

分 类 号：O433.1[机械工程—光学工程]