结合小波分析法与导数光声光谱技术测量弱光谱信号的实验研究  

Retrieving the weak signals of photoacoustic spectroscopy precisely by wavelet analysis and first-derivative method

作　　者：郑金存[1] 张慧[2] 邵平[1] 

机构地区：[1]玉林师范学院物理与信息科学系,广西玉林537000 [2]玉林师范学院化学与生物系,广西玉林537000

出　　处：《大学物理》2010年第1期42-45,共4页College Physics

基　　金：广西教育厅面上项目(200807MS125)资助;玉林师范学院青年基金资助项目(2008YJQN03)

摘　　要：结合导数光声光谱技术与小波分析方法,精确测量了光声光谱中的弱光谱信号.首先利用自己设计的仪器装置实现光声光谱的一阶导数,在此基础上,根据导数光声光谱的数据选择合理的分析小波,将光声光谱信号分解为不同频率信号的叠加,被分解的信号满足线性性质且原信号的峰值信息保持不变,由频率的差异可区分出光声信号和噪声信号,从而提取出光声光谱中的弱光谱信号.结合物理方法与软件方法的分析结果,准确地测量了氙灯的输出光声光谱中3个不明显的弱峰值,位置分别为699.7nm、753.4nm和776.5nm.该方法可以更准确地提取出光声光谱的峰值信息,有效地提高了光声光谱的测量精度,为光声光谱分析法在生物医学及化学分析中的应用提供了一种更精确的分析方法.Based on wavelet transform and first-derivative photoacoustic spectroscopy（PAS）, a new analytical method for PAS is presented. An experiment setup is specially designed to get the first-derivative spectrum,thus the sensitivity of PAS analysis is improved. In order to increase the accuracy of measurement,the wavelet transform is introduced to decompose the PAS signal into localized detail signals according to the frequency,noise and PAS signals can be discriminated by the difference of frequency,and the position of PAS peaks in time axis and the original linearity are not changed,hence the useful information can be obtained by this decomposed result. Due to the wave- let method and derivative PAS method,three weak absorption peaks which hidden in PAS of Xenon lamp output are precisely retrieved,whose wavelengths are 669.7 nm,753.4 nm and 776.5 nm, respectively. This new analytical method,which takes advantage of the virtues of physics method and software technique, can be used to improve the sensitivity and accuracy of PAS analysis effectively, and it is expected to be a useful analysis tool in biology medical and chemistry analysis.

关 键 词：光谱分析 光声光谱 导数光声光谱 小波分析 

分 类 号：O433.4[机械工程—光学工程]