Measurement of aerosol optical extinction using diode laser cavity ringdown spectroscopy  

作　　者：LIU YingDi ZHANG JingSong 

机构地区：[1]Department of Chemistry and Air Pollution Research Center, University of California

出　　处：《Chinese Science Bulletin》2013年第20期2440-2446,共7页

基　　金：supported by the US National Science Foundation (CHE1214157);W. M. Keck Foundation

摘　　要：Accurate measurement of optical extinction of atmospheric aerosols is important for quantifying the direct climate effects of aerosols. A portable cavity ringdown spectrometer utilizing a modulated multimode blue diode laser (linewidth ～0.2 nm) is developed to measure the aerosol optical extinction. Laboratory generated ammonia sulfate particles (<1 μm in diameter) are characterized, with good agreements between the experimental measurements and Mie theory calculations. An optical extinction detection sensitivity of 0.24 Mm-1 (1σ) is achieved. Measurements of ambient aerosols are also carried out. This study demonstrates the feasibility of a compact, multimode diode laser cavity ringdown spectrometer for sensitive measurements of the optical extinction of atmospheric aerosols.Accurate measurement of optical extinction of atmospheric aerosols is important for quantifying the direct climate effects of aerosols. A portable cavity ringdown spectrometer utilizing a modulated multimode blue diode laser （linewidth -0.2 nm） is developed to measure the aerosol optical extinction. Laboratory generated ammonia sulfate particles （〈1 υm in diameter） are characterized, with good agreements between the experimental measurements and Mie theory calculations. An optical extinction detection sensitivity of 0.24 Mm-1 （lσ） is achieved. Measurements of ambient aerosols are also carded out. This study demonstrates the feasibility of a compact, multimode diode laser cavity ringdown spectrometer for sensitive measurements of the optical extinction of atmospheric aerosols.

关 键 词：蓝色激光二极管 大气气溶胶 光谱测量 光腔衰荡 消光 硫酸铵颗粒 MIE理论 检测灵敏度 

分 类 号：X831[环境科学与工程—环境工程] O657.3[理学—分析化学]