基于石英增强光声光谱的氧气探测  

Oxygen Detection Based on Quartz-Enhanced Photoacoustic Spectroscopy

作　　者：卢俊城 吴华坤 章艺欣 刘苏瑞 赵家胜 吴琼[1] 刘雯 Lu Juncheng;Wu Huakun;Zhang Yixin;Liu Surui;Zhao Jiasheng;Wu Qiong;Liu Wen(College of Physics and Electronic Information Engineering,Zhejiang Normal University,Jinhua 321004,Zhejiang,China)

机构地区：[1]浙江师范大学物理与电子信息工程学院,浙江金华321004

出　　处：《光学学报》2025年第2期299-306,共8页Acta Optica Sinica

基　　金：浙江省自然科学基金(LQ21F050007)。

摘　　要：基于石英增强光声光谱(QEPAS)技术和共轴式谐振管配置,开发了一种体积小、灵敏度高和寿命长的共轴式QEPAS氧气(O_(2))检测系统。采用中心波长为763 nm的高功率可调谐半导体激光器,结合波长调制光谱技术对O_(2)进行了探测,并研究了水蒸气(H_(2)O)对O_(2)分子弛豫的影响。结果表明,在O_(2)的体积分数为21%的气体混合物中加入体积分数为0.8%的H_(2)O后,O_(2)的光声信号强度提高了约7倍。在12.5 s的积分时间下,H_(2)O的体积分数保持在1.6%,系统的线性度为0.999,O_(2)的检测限可达9.25×10^(-4)。系统的归一化噪声等效吸收系数为4.70×10^(-9)W·cm^(-1)·Hz-^(1/2)。通过Allan方差曲线分析获得了系统的最佳积分时间为925 s,最小可探测极限为5.5×10^(-4)。Objective Oxygen sensors play a key role in various applications,including industrial process control,medical devices,and biomanufacturing.In these contexts,high sensitivity detection of low concentration oxygen is essential for tasks such as monitoring residual oxygen in syringe vials,controlling combustion processes,tracking metabolic processes,and ensuring air quality in food packaging.Current trace oxygen sensors primarily utilize electrochemical,zirconia,and paramagnetic technologies.Electrochemical sensors are the most widely used due to their low cost and high precision,but they suffer from long response time and limited lifetime.While zirconia and paramagnetic sensors offer longer operating lives,their high operating temperatures and costs restrict their broader application.Therefore,developing trace oxygen sensors that provide long lifetimes,low costs,fast responses,and high detection limits at room temperature is of significant practical importance.Methods We develop a compact,high-sensitivity oxygen(O_(2))detection system using the quartz-enhanced photoacoustic spectroscopy(QEPAS)technique and an on-beam resonator tube configuration.A high-power tunable diode laser with a center wavelength of 763 nm is used in combination with wavelength modulation spectroscopy to detect O_(2),and we investigate the influence of water vapor(H_(2)O)on O_(2)molecular relaxation.We also explore the linearity,stability,and minimum detection limit of the system.Results and Discussions To optimize the second harmonic photoacoustic signal,we adjust the wavelength modulation depth of the QEPAS system.Figure 4(a)shows the relationship between photoacoustic signal intensity and the modulation amplitude.From Fig.4(b),the oxygen photoacoustic amplitude reaches a maximum of 2.24 V at a modulation amplitude of 55 mV.We determine this modulation depth as optimal and conduct subsequent experiments under these conditions.Oxygen has a low relaxation rate,while water vapor exhibits a high relaxation rate,making H_(2)O an effective cataly

关 键 词：石英增强光声光谱 波长调制光谱技术 氧气检测 弛豫率 

分 类 号：O433[机械工程—光学工程]