激光与光电子学进展, 2019, 56 (21): 213001, 网络出版: 2019-11-02
基于石英增强光声光谱的H2S痕量气体检测研究 下载: 1284次
Detection of Trace Sulfur Dioxide Gas Using Quartz-Enhanced Photoacoustic Spectroscopy
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
摘要
以输出波长为1578 nm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4 mm、内径为0.7 mm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。
Abstract
By combining the wavelength demodulation and second harmonics, the trace H2S 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 H2S gas under optimal experimental conditions. The results denote that the second harmonic signal of the QEPAS system exhibits a strongly linear relation with the H2S gas concentration, and a detection limit of 19.3×10 -6 is obtained.
张蕾蕾, 刘家祥, 朱之贞, 方勇华, 吴越, 杨文康, 陶孟琪, 宁志强. 基于石英增强光声光谱的H2S痕量气体检测研究[J]. 激光与光电子学进展, 2019, 56(21): 213001. Leilei Zhang, Jiaxiang Liu, Zhizhen Zhu, Yonghua Fang, Yue Wu, Wenkang Yang, Mengqi Tao, Zhiqiang Ning. Detection of Trace Sulfur Dioxide Gas Using Quartz-Enhanced Photoacoustic Spectroscopy[J]. Laser & Optoelectronics Progress, 2019, 56(21): 213001.