摘要
基于离轴积分腔输出光谱技术,设计并研制了一种红外二氧化碳(CO2)传感系统.采用中心波长为1572 nm的分布式反馈激光器,选择6359.96 cm-1处CO2的吸收谱线作为目标谱线.研制的谐振腔长度为60 cm,测得的有效光程为1200 m.采用波长调制光谱技术与直接吸收光谱技术分别测量CO2的吸收光谱,前者测得的光谱信号的信噪比为130,优于后者的信噪比80.将波长调制光谱技术与离轴积分腔技术相结合,利用LabVIEW软件提取二次谐波信号的幅值.利用配备的气体样品,开展了传感器标定、稳定性及动态响应性能测试等实验.使用纯氮气(N2)进行了稳定性测试,艾伦方差表明,当平均时间为96 s时,系统的检测下限为5.1×10-6;当气体流速为500 sccm时,实验测得的响应时间小于20 s.利用该系统开展了连续16.5 h的大气CO2浓度在线实时监测和人呼出气体中的CO2含量检测,均呈现出较好的性能.该系统具有易操作、响应快、灵敏度高等优点,未来可广泛应用于大气环境检测、医疗诊断等方面.
Based on the off-axis integrated cavity output spectroscopy technology,an infrared carbon dioxide(CO2)sensing system was developed.A distributed feedback laser centered at 1572 nm was used,and the absorption line of CO2 at 6359.96 cm-1 was selected as the target line.The length of the resonant cavity developed is 60 cm,and the measured effective optical path is 1200 m.Using the wavelength modulation spectroscopy technique and the direct absorption spectroscopy technique to measure the absorption spectrum of CO2,the signal-to-noise ratio of the spectral signal of the former was 130,which was better than the latter’s signal-to-noise ratio of 80.The wavelength modulation technology was combined with the off-axis integrating cavity technology,and LabVIEW software was used to extract the second harmonic amplitude.Using the equipped gas samples,performance tests such as sensor calibration,stability and dynamic response were carried out.Using pure nitrogen(N2)for stability test,Allan variance showes that the detection limit of the system is 5.1×10-6 when the average time is 96 s.When the gas flow rate is 500 sccm,the experimental response time is less than 20 s.The system was used to carry out continuous online real-time monitoring of atmospheric CO2 concentration for 16.5 hours and detection of CO2 content in human breathing gas,both showing good performance.The system has the advantages of easy operation,fast response and high sensitivity,and can be widely used in atmospheric environment detection and medical diagnosis in the future.
作者
刘梓迪
郑凯元
张海鹏
郑传涛
王一丁
LIU Zi-di;ZHENG Kai-yuan;ZHANG Hai-peng;ZHENG Chuan-tao;WANG Yi-ding(State Key Laboratory of Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2020年第11期181-189,共9页
Acta Photonica Sinica
基金
国家重点研发计划(No.2017YFB0405300)
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)。
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
波长调制技术
CO2检测
Gas sensor
Infrared absorption spectroscopy
Off-axis integrated cavity output spectroscopy
Wavelength modulation
CO2 detection
