腔增强吸收光谱技术在大气环境研究中的应用进展

大气污染是全球性环境问题,针对大气环境污染物检测技术的发展对大气环境研究至关重要.光谱分析方法因其具有特异性选择、高精度、高时间分辨等优势,已被广泛应用于大气污染物检测领域.腔增强吸收光谱(CEAS)技术由腔衰荡光谱(CRDS)技术发展而来,是通过测量透过高精细度谐振腔的光强获得分子吸收信息的高灵敏度探测技术.该技术自...

Application Progress of Cavity-Enhanced Absorption Spectroscopy (CEAS) in Atmospheric Environment Research

Atmospheric pollution is a global environmental problem, and the development of detection technology for atmospheric environmental pollutants is crucial to atmospheric environmental research. Spectral analysis methods have been widely used in atmospheric pollutant detection because of their specific selection, high accuracy, and high time resolution. Cavity-enhanced absorption spectroscopy (CEAS) is developed from cavity ring-down spectroscopy (CRDS). A high-sensitivity detection technique obtains molecular absorption information by measuring the light intensity through a high-definition resonant cavity. In the past two decades since its introduction, this technology has become an important method for trace gas detection in atmospheric environment research because of its advantages such as low cost, simple operation, high sensitivity, and strong adaptability. This paper introduces the two CEAS technology principles and basic device structure based on coherent and incoherent light sources. Among them, incoherent broadband cavity absorption-enhanced absorption spectroscopy (IBBCEAS) technology mainly uses LED and short-arc xenon lamps as light sources, which has lower cost and can detect the spectral range of tens of nanometers, so it is more widely used in atmospheric research. This paper reviews the application of CEAS technology developed by domestic and foreign research groups detecting nitrogen oxides (NO₂, NO₃, N₂O₅, HONO), volatile organic gases (formaldehyde, glyoxal, methylglyoxal, methane, ethylene), halogen elements (I₂, Br₂), halogen oxides (OIO, IO, BrO), ozone (O₃), aerosol and other pollutants. Meanwhile, in thiswork, we summarized the improvement and optimization of CEAS sensitivity from the aspects of the light source, detector, optical cavity structure. This paper focuses on CEAS detection ability not only under laboratory conditions but also in field campaigns. Finally, some prospects are made from the aspects of system optimization and the future application trend of CEAS technology.