基于远距离激光测振仪的痕量危险品探测  

Trace Hazardous Substance Detection Based on Long-Distance Laser Vibrometer

作　　者：刘晓利[1] 王紫薇 傅愉 Liu Xiaoli;Wang Ziwei;Fu Yu(Shenzhen Key Laboratory of Intelligent Optical Measurement and Detection,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学物理与光电工程学院深圳市智能光测与感知重点实验室,广东深圳518060

出　　处：《光学学报》2023年第13期152-159,共8页Acta Optica Sinica

基　　金：国家自然科学基金(11972235);深圳市基础研究项目(JCYJ20220531101204010)。

摘　　要：光声/光热光谱技术已经广泛应用于痕量危险化学品和爆炸物的探测,并显示出高效的探测能力。然而,该技术通常需要在光声池中进行分析,并使用高灵敏度麦克风或压电传感器记录振动信号,因此不适用于在安全距离外的开放环境中探测泄漏的危险物质或爆炸物。为此,利用强度调制的量子级联激光器(QCL)激发微量固体(聚四氟乙烯)和气体(丙酮)的光声效应,借助自主研发的远距离激光多普勒测振仪(LDV)对QCL产生的光振动信号进行检测。通过扫描QCL的波长,测量振动信号的幅值并获取光声光谱,其结果与傅里叶变换红外光谱的结果高度一致。实验结果表明,自制的远距离LDV可以在距离达200 m的开放环境下有效地检测痕量固态和气态化学品的光声信号。Objective The ability to rapidly detect and identify hazardous materials,such as explosives and hazardous gases,is a critical technology that can facilitate security screening in the global effort against terrorism.Recent R&D works focus on technologies to perform standoff sensing of hazardous materials in the open environment without any sample preparation.In this work,a long-distance laser Doppler vibrometer developed by China is applied as a sensor to detect the photoacoustic signal on solid and gaseous chemicals.Methods Photoacoustic/photothermal(PA/PT)techniques can provide sensitive non-contact solutions to overcome this challenge at a meaningful standoff distance.Since the last century,PA spectroscopy(PAS)has been applied in many applications for solid,liquid,and gas evaluation.Conventional PAS requires prior preparation of analyte samples,and the measurement is conducted within a controlled environment,such as a well-isolated photoacoustic cell.The response signal is captured by a highly sensitive microphone or any other form of sensor located close to or in direct contact with the sample.Hence,commercial PAS equipment limits the technique in a laboratory environment.In recent years,research focuses on improving the excitation source and the detection technology in the open air.Two trends have been observed in the research area of standoff detection of chemicals and explosives:(1)Quantum cascade laser(QCL)becomes a more practical excitation source due to its high power,broadly tunable wavelength in the mid-infrared ray(IR)range,and compact size over other light sources such as optical parametric oscillators(OPOs);(2)non-contact optical detection techniques,such as thermal imaging and laser interferometry become generally accepted methods for standoff detection of PA/PT signals in the open air.Recently,a conventional and mature interferometric system,namely a laser Doppler vibrometer(LDV),has been applied to detect the photo-vibrational signal on solid and liquid due to the PA effect.The standoff distance

关 键 词：干涉测量术 光声效应 激光多普勒测振仪 振动分析 

分 类 号：O436[机械工程—光学工程]