双通道离轴石英增强光声光谱气体传感器  

Dual-pass Off-beam Quartz-enhanced Photoacoustic Spectroscopic Gas Sensor

作　　者：隋心 马琰铭 刘孝腾 张磊 宋芳 李秀英 徐琳 王一丁 郑传涛 SUI Xin;MA Yanming;LIU Xiaoteng;ZHANG Lei;SONG Fang;LI Xiuying;XU Lin;WANG Yiding;ZHENG Chuantao(State Key Laboratory of Integrated Optoelectronics,Jilin University Region,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China;Jilin Provincial Engineering Research Center of Infrared Gas Sensing Technique,Changchun 130012,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联合实验室吉林大学实验区,长春130012 [2]吉林省红外气体传感技术工程研究中心,长春130012

出　　处：《光子学报》2024年第8期112-121,共10页Acta Photonica Sinica

基　　金：国家重点研发计划(No.20213201903);国家自然科学基金(Nos.62175087,62235016,61960206004,62105118);吉林省科技发展计划(No.20230201054GX);长春市重点研发项目(No.21ZGN24)。

摘　　要：为了消除杂散光激励石英音叉产生的光热信号对气体检测性能的影响,采用离轴配置谐振管,将两只中央开有槽口的谐振管平行于音叉正面放置在两侧,从而实现了探测光束与石英音叉的隔离,同时降低了系统组装和光路调整的复杂度。将光纤准直器、谐振管、石英音叉、直角棱镜和不锈钢气室进行集成,研制了一种尺寸仅为5.4 cm×4.0 cm×1.5 cm的光声检测模块,在此基础上,建立了一种光声光谱气体检测系统,采用中心波长为1533 nm的分布反馈激光器,通过检测乙炔气体来评估系统性能。实验结果表明,光声信号与气体浓度之间呈现良好的线性-关系,线性拟合优度为0.991。系统的1σ检测下限和对应归一化噪声等效吸收系数分别为11.6×10^(-6)和6.7×10^(-9)W·cm^(-1)·Hz^(-1/2)。对系统的Allan方差分析结果表明,当平均时间为0.5 s时,系统的检测下限为10.22×10^(-6),当平均时间为50 s时,系统检测下限可以达到1.20×10^(-6)。所研制的微小型双通道离轴石英增强光声光谱传感器系统具有体积小、价格低廉、灵敏度高等优点,有利于实现便携式气体检测。The detection of trace gases is of great significance in the fields of fire alarm,industrial production,biomedicine and so on.Long-term and stable monitoring is needed for the explosive,toxic and harmful gases.Acetylene(C2H2),as a characteristic gas produced in transformer overheating and discharge,is an important parameter to monitor transformer faults.Optical gas sensors based on Lambert-Beer law are more suitable for real-time and long-term gas detection because of their advantages such as high sensitivity,small drift and non-invasive.In 2002,Quartz Enhanced Photoacoustic Spectroscopy(QEPAS)based on Quartz Tuning Fork(QTF)was proposed.Quartz tuning fork has the advantages of high-quality factor,stable resonant frequency and narrow resonant band width,so it has higher sensitivity and stronger anti-environmental noise ability than traditional PAS.In addition,s mall s ize a nd low c ost o f QTF make a QEPAS system small,portable and easy to integrate.To further improve the detection sensitivity of QEPAS system,methods such as using acoustic microresonator(AmR),customizing special-size QTFs and multi-channel detection were widely used.Sensor systems based on QEPAS shows excellent performance in gas detection and provide an excellent scheme for real-time and long-term monitoring of trace gases.However,there is still a problem t hat part of the laser power will lose due to partial irradiation on the QTF surface,which is not conducive to improving the detection sensitivity.In order to reduce the difficulty of system assembly and optical path adjustment,and avoid the photothermal effect caused by laser beam irradiation on the surface of the tuning fork,off-beam resonant tube configuration is used to isolate the detection beam from the quartz tuning fork,and two resonant tubes with central grooves are placed on both front sides of the tuning fork.To further improve the detection sensitivity,the optical path is equipped with a right-angle prism to realize dual-pass measurement.Optical fiber collimator,resonant tube,QTF,

关 键 词：石英增强光声光谱技术 气体传感器 波长调制技术 乙炔 石英音叉 

分 类 号：O433.1[机械工程—光学工程]