摘要
基于腔增强吸收光谱(CEAS)技术和波长调制光谱(WMS)技术,搭建了腔增强光谱测量系统,并采用该系统实现了CO体积分数的测量。实验中使用中心波长为2.3μm的分布式反馈激光器作为光源,以反射率为99.8%的两片高反镜构建了基长为30cm的光学腔,达到了147.15m的有效吸收路径;在此基础上,利用4297.705 cm^(-1)处的CO吸收谱线作为传感目标,实现了对CO的探测。利用CO体积分数不同的CO+N_(2)的混合气体对系统的测量准确度进行验证,结果显示,测量值与参考值大小基本吻合,测量误差约为0.2%,证实了所搭建系统的测量准确性。利用体积分数为3×10^(-6)的CO气体的二次谐波信号对系统的探测极限进行了分析,得到系统对CO的探测极限为138×10^(-9)。
Objective Based on cavity-enhanced absorption spectroscopy(CEAS) and wavelength modulated spectroscopy(WMS)technology,a cavity-enhanced spectrum measurement system was built to measure the volume fraction of CO gas.In an experiment,a distributed feedback laser(DFB) laser with a central wavelength of 2.3 μm was used as the light source,and an optical cavity with a base length of 30 cm was constructed with two highly reflective mirrors with a reflectivity of 99.8%.An effective absorption path of 147.15 m was achieved.On this basis,CO was detected using the CO absorption spectral line at 4297.705 cm^(-1) as the sensing target.In the experiment,the measurement accuracy of the system was verified using CO and N_(2) gas mixtures with different volume fractions of CO.The measured value was consistent with the reference value,and the measurement error was approximately 0.2%,which confirmed the measurement accuracy of the system.The detection limit of the system was analyzed using the second harmonic signal of CO gas with a volume fraction of 3×10^(-6),and the lowest detectable CO volume fraction with the system was 138×10^(-9).Methods The optical cavity in the sealed box was composed of two highly reflective mirrors.The length of the cavity was 30 cm,diameter of the highly reflective mirrors specified by the manufacturer was 25.4 mm,and radius of curvature was 1 m.Their reflectivity reached 99.8% in a wavelength range of 1.9-2.3 μm.In the experiment,the laser output from the 2.3 μm DFB laser was divided into two parts using a fiber beam splitter.One part was passed through an oscilloscope(Bristol 671) to obtain the real-time scanning output wavelength of the laser,and the other part passed through the sealed box made of tempered glass.The laser beam entered the optical cavity through the sealed box.Then,after multiple reflections in the cavity,it was transmitted from the other end and converged in the InGaAs detector through a lens with focal length of 5 mm for detection.After the detector signal was sent to the inp
作者
王宣
高光珍
龙芳宇
杨玉冰
蔡廷栋
Wang Xuan;Gao Guangzhen;Long Fangyu;Yang Yubing;Cai Tingdong(School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou 221116,Jiangsu,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2023年第13期221-228,共8页
Chinese Journal of Lasers
基金
国家自然科学基金(42275136,62275110,61875079,61805110,61475068,11104237)
江苏省碳达峰碳中和科技创新专项资金(BE2022314)
江苏省重点研发计划(社会发展)专项资金(BE2021634)
江苏师范大学研究生科研与实践创新计划(2022XKT1346)。
关键词
光谱学
腔增强吸收光谱技术
波长调制光谱
CO气体
体积分数测量
spectroscopy
cavity-enhanced absorption spectroscopy
wavelength modulated spectrum
carbon monoxide gas
volume fractionmeasurement
