可调谐半导体激光吸收光谱中的吸光度反演算法研究  

Study on the Arithmetic of Absorbance Inversion Based on Tunable Diode-Laser Absorption Spectroscopy

作　　者：许振宇[1] 刘文清[1] 阚瑞峰[1] 张玉钧[1] 刘建国[1] 张帅[1] 束小文[1] 耿辉[1] 何莹[1] 汤媛媛[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所环境光学与技术重点实验室,安徽合肥230031

出　　处：《光谱学与光谱分析》2010年第8期2201-2204,共4页Spectroscopy and Spectral Analysis

基　　金：中国科学院知识创新工程重要方向性项目(KGCX2-YW-121-1);中国科学院国防预研基金项目(CXJJ-09-M38)资助

摘　　要：可调谐半导体激光吸收光谱具有高分辨、高灵敏度和快速测量等特点,已经在环境检测、工业过程检测等方面得到广泛应用。在直接吸收光谱技术中,吸光度曲线以及积分吸光度的确定对于气体浓度反演、线强校正等都有重要的作用。对激光直接吸收光谱中吸光度和吸光度积分反演算法进行了研究,采用分段多项式基线拟合方法来消除激光器光强波动的影响,得到吸光度,再用非线性拟合Levenberg-Marquardt算法进行线形拟合来获取积分吸光度。通过水气吸收谱线的检测对算法进行了验证。Tunable diode-laser Absorption spectroscopy techniques have been widely used in many regions,such as environmental monitoring and detection of industrial process,due to their high spectral resolution,high sensitivity,fast time response and non-intrusive character.It’s important to obtain Absorbance curve and integrated Absorbance for gas concentration inversion and line strength calibration in direct-Absorption spectroscopy techniques.An approach was taken to process the laser direct Absorption spectrum.First a low-order polynomial baseline fitting was carried on sub-regions of the transmitted signal to eliminate the effect of diode-laser output fluctuation and obtain the Absorbance curve.Then integrated Absorbance can be inverted through line-shape fitting using Levenberg-Marquardt non-linear least-squares fitting method.This approach was verified by experimental processing of Absorption lines of water vapor.

关 键 词：吸光度 基线拟合 非线性最小二乘法 

分 类 号：O433.5[机械工程—光学工程]