非相干光宽带腔增强吸收光谱技术应用于SO_2弱吸收的测量  

An Incoherent Broadband Optical Cavity Spectroscopy for Measuring Weak Absorption Cross Section of Sulfur Dioxide

作　　者：段俊 秦敏 方武 胡仁志 卢雪 沈兰兰 王丹[1] 谢品华[1,2] 刘建国[1,2] 刘文清[1,2] 

机构地区：[1]中国科学院安徽光学精密机械研究所,中国科学院环境光学与技术重点实验室,安徽合肥230031 [2]中国科学技术大学环境科学与光电技术学院,安徽合肥230026

出　　处：《光谱学与光谱分析》2016年第2期466-470,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(61275151);中国科学院战略性先导科技专项项目(B类)(XDB05040200);国家高技术研究发展计划(863计划)项目(2014AA06A508)资助

摘　　要：非相干光宽带腔增强吸收光谱作为高灵敏检测技术,已成功应用于多种大气痕量气体浓度的测量。根据腔增强吸收光谱技术测量原理可知,若已知测量气体准确浓度,镜片反射率随波长的变化曲线、有效吸收长度、光学腔内有无测量气体吸收前后的光辐射变化,可测量出待测气体的吸收截面。SO_2由于a^3 B_1—X^1 A_1自旋禁阻跃迁,在345~420nm波段吸收截面较低(~10^(-22) cm2/molecule),其测量有一定难度,而准确的弱吸收截面对于卫星反演大气痕量气体浓度以及大气研究等方面均有重要意义。采用365nm LED光源的宽带腔增强吸收光谱实验装置测量357~385nm波段范围SO_2的弱吸收,获得该波段SO_2弱吸收截面,并与已公开发表的SO_2吸收截面进行对比,相关系数r为0.997 3,验证了非相干光宽带腔增强吸收光谱技术准确测量气体弱吸收截面的适用性。As a highly sensitive detection technology,incoherent broadband cavity enhanced absorption spectroscopy（IBBCEAS）have successfully measured a variety of trace gases.According to the principle of cavity enhanced absorption spectroscopy,if the accurate concentration of the target gas,the curve of the mirror reflectance,effective absorption path length,the light intensity of the absorbing gas and non-absorbing gas are known,the absorption cross section of the absorption gas can be measured.The accurate measurements of absorption cross section are necessary for satellite retrievals of atmospheric trace gases and the atmospheric research.This paper describes an incoherent broadband cavity enhanced absorption spectroscopy（IBBCEAS）instrument with 365 nm LED as the light source for measuring absorption cross section of SO_2 from 357to 385 nm which is arising from the spin-forbidden a^3 B_1—X^1 A_1 transition.In comparison to the literature absorption cross section of SO_2,and correlation coefficient ris 0.997 3.The result shows the potential of the IBBCEAS system for measuring weak absorption cross section.

关 键 词：吸收截面 非相干光宽带腔增强吸收光谱 SO_2 

分 类 号：O433[机械工程—光学工程]