基于腔增强激光光谱的水中溶解甲烷传感系统  

Sensing System of Dissolved Methane in Water Based on Cavity-enhanced Laser Spectroscopy

作　　者：陈稳稳 郑凯元 曹延伟 陈奕汐 郑传涛[1] 王一丁[1] CHEN Wenwen;ZHENG Kaiyuan;CAO Yanwei;CHEN Yixi;ZHENG Chuantao;WANG Yiding(State Key Laboratory of Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China;Chinese People's Liberation Army 96901 Unit 24,Beijing 100089,China;The First Military Representative Office of Rocket Army Equipment Department in Wuhan,Wuhan 430022,China)

机构地区：[1]吉林大学电子科学与工程学院集成光电子学国家重点实验室,长春130012 [2]中国人民解放军96901部队24分队,北京100089 [3]火箭军装备部驻武汉地区第一军事代表室,武汉430022

出　　处：《光子学报》2021年第9期168-176,共9页Acta Photonica Sinica

基　　金：国家重点研发计划(No.2016YFC0303902);国家自然科学基金(Nos.61775079,61627823,61960206004);吉林省科技发展计划(Nos.20180201046GX,20190101016JH,20200401059GX)。

摘　　要：为探测水中甲烷气体浓度,研制了一种基于离轴积分腔输出光谱的水中溶解甲烷传感系统。系统由分布式反馈激光器(中心波长为1653 nm)、激光器温度控制模块、激光器电流驱动模块、谐振腔/气室、光电探测器、数据采集模块、数据处理模块和气液分离模块构成。利用配备的甲烷气体样品和纯氮气(N2),分别开展系统有效光程标定、直接吸收光谱信号的标定和稳定性测试等实验。使用浓度为10×10^(-6)的甲烷气体样品标定了系统有效光程,约为1906 m。将纯氮气作为目标气体,测量系统的稳定性。Allan方差分析结果表明,当积分时间为2 s时,系统检测灵敏度为92.8×10^(-9),当积分时间增加到134 s,系统的灵敏度可提高到13.2×10^(-9)。利用该系统开展自来水、雨水和湖水样品中溶解甲烷的浓度检测实验,结果证实了该技术及系统的工程实用价值。该研究及相关结果为水质检测和天然气水合物等清洁能源的勘探开发奠定了良好的基础。In order to detect the concentration of methane in water,a sensor system of dissolved methane in water based on off-axis integrated cavity output spectroscopy is developed in this paper.A distributed feedback laser(center wavelength,1653 nm),a laser temperature control module,a laser current drive module,a resonator cavity/gas chamber,a photoelectric detector,a data acquisition module,a data processing module and a gas-liquid separation module were included in the system.Experiments including calibration of effective optical path length,calibration of direct absorption signal,and stability test were carried out by using methane gas samples and pure nitrogen(N2).The effective optical path length of the cavity is calibrated using a methane sample with a concentration level of 10×10^(-6),which is determined to be 1906 m.Using pure nitrogen as the target gas,the stability of the system is measured.The results of Allan variance analysis show that when the averaging time is 2 s,the detection sensitivity is 92.8×10^(-9),and the sensitivity of the system can be improved to 13.2×10^(-9) with an averaging time of 134 s.The system was used to measure the concentration of the dissolved methane in tap water,rainwater and lake water,and the results confirmed the engineering practical value of the technique and system.The research work and related results have laid a good foundation for water quality detection and exploration of clean energy such as natural gas hydrate.

关 键 词：气体传感器 红外吸收光谱 离轴积分腔输出光谱技术 直接吸收光谱技术 甲烷检测 

分 类 号：TN219[电子电信—物理电子学]