光纤耦合的全固态中红外QEPAS光声探测模块  

All-Solid-State Mid-Infrared Fiber-Coupled QEPAS Photoacoustic Detection Module

作　　者：刘怡华 郑华丹 谢戆志 林灏杨 杨志飞 吴潜 朱文国 钟永春[1,2] 余健辉 陈哲[1,2] Liu Yihua;Zheng Huadan;Xie Zhuangzhi;Lin Haoyang;Yang Zhifei;Wu Qian;Zhu Wenguo;Zhong Yongchun;Yu Jianhui;Chen Zhe(Department of Optoelectronic Engineering,College of Science&Engineering,Jinan University,Guangzhou,Guangdong 510632,China;Key Laboratory of Optical Fiber Sensing and Communication Technology of Guangdong Province,Jinan University,Guangzhou,Guangdong 510632,China)

机构地区：[1]暨南大学理工学院光电工程系,广东广州510632 [2]暨南大学广东省光纤传感与通信技术重点实验室,广东广州510632

出　　处：《光学学报》2021年第20期208-216,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61705086,61771222,62005105);国家重点研发计划(2019YFE0118200);装备预研教育部联合基金(6141A02022124);广东省自然科学基金(2020B1515020024,2017A030313375,2019A1515011380);广东省重点领域研发计划(2019B010138004,2017A010102006,2015B010125007);中央高校基本科研业务经费资助项目(21619402,11618413)。

摘　　要：石英增强光声光谱(QEPAS)技术是近年来发展迅速的一种气体检测技术,具有灵敏度高、设备体积小、对环境噪声免疫等优点。本课题组设计了一种光纤耦合的全固态中红外QEPAS光声探测模块,并基于气体热动力学和一维声学谐振腔理论,利用COMSOL软件对探测模块的声压分布及声压级进行了研究;然后设计并加工了光机电一体化探测模块,将声学谐振腔、光声池、光纤模块和前置放大模块集成一体,使该模块具有易于准直、稳定性高、抗干扰能力强等特点。采用中心波长为2μm的高功率中红外分布反馈式激光器,结合波长调制技术,对CO_(2)进行了探测,结果表明,在1 s的积分时间下获得了3.7×10^(-5)的探测极限。通过Allan方差分析发现,积分时间为1123 s时,系统的探测极限可以达到1.34×10^(-6)。采用基于该模块的QEPAS系统可以实现对室内CO2浓度的实时监测。Quartz-enhanced photoacoustic spectroscopy(QEPAS) is a gas detection technology that has developed rapidly in recent years. It has the advantages of high sensitivity, small equipment size, and immunity to environmental noise. We design an all-solid-state mid-infrared fiber-coupled QEPAS photoacoustic detection module. Under theories of gas thermodynamics and one-dimensional acoustic resonator, the sound pressure distribution and level of the detection module are simulated using COMSOL software. An optomechatronic detection module is then designed and processed. It integrates the acoustic resonator, photoacoustic cell, optical fiber module, and pre-amplification module for easy collimation, high stability, and strong anti-interference ability. With a high-power mid-infrared DFB laser at a central wavelength of 2 μm as the light source, CO_(2) detection is carried out via wavelength modulation technology. As a result, a detection limit of 3.7×10^(-5)is obtained at an integration time of 1 s. Allan variance analysis shows that when the integration time is 1123 s, the detection limit of the system can reach 1.34×10^(-6). The QEPAS system built on this module can be used to conduct real-time monitoring of indoor CO_(2) concentration.

关 键 词：光谱学 石英增强光声光谱 光声光谱 音叉式石英晶振 光声探测模块 

分 类 号：O433[机械工程—光学工程]