摘要
以输出波长为1578nm的分布式反馈半导体激光器作为激发光源,结合波长调制及二次谐波技术对H2S痕量气体进行基于石英增强光声光谱技术(QEPAS)的检测研究。采用有限元分析法对QEPAS中常用的石英音叉进行仿真计算,得到石英音叉的前6阶模态振型与共振频率。实验中,添加了长为4mm、内径为0.7mm的声波微共振腔,优化了跨阻放大电路,在最优实验条件下对H2S气体进行检测,检测结果表明,QEPAS系统的二次谐波信号与H2S浓度具有良好的线性关系,获得的探测极限为19.3×10^-6。
By combining the wavelength demodulation and second harmonics,the trace H2 S gas is detected based on the quartz-enhanced photoacoustic spectroscopy(QEPAS).A distributed feedback semiconductor laser with an output wavelength of 1578 nm is used as the excitation source.Furthermore,a finite element analysis method is used in the simulation calculation for a quartz tuning fork,typically used in QEPAS systems,to obtain its first six modes and resonance frequencies.In an experiment,an acoustic micro-resonator with a length of 4 mm and an inner diameter of 0.7 mm is added,and a transimpedance amplifying circuit is optimized to detect the H2 S gas under optimal experimental conditions.The results denote that the second harmonic signal of the QEPAS system exhibits a strongly linear relation with the H2 S gas concentration,and a detection limit of 19.3×10^-6 is obtained.
作者
张蕾蕾
刘家祥
朱之贞
方勇华
吴越
杨文康
陶孟琪
宁志强
Zhang Leilei;Liu Jiaxiang;Zhu Zhizhen;Fang Yonghua;Wu Yue;Yang Wenkang;Tao Mengqi;Ning Zhiqiang(School of Environmental Science and Optoelectronic Technology,University of Science and Technology of Chiyia,Hefei,Anhui 230026,China;Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei,Anhui 230031,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2019年第21期245-251,共7页
Laser & Optoelectronics Progress
关键词
光谱学
微量气体检测
波长调制
石英音叉
微共振腔
spectroscopy
trace gas detection
wavelength modulation
quartz tuning fork
micro-resonator
