由激光诱导荧光方法探测光碎片分子取向的理论研究

采用密度矩阵方法 ,推导了从激光诱导荧光 (LIF)强度中抽出光碎片取向参数的表达式 .光碎片的取向由分子态多极矩描述 .用于解离母分子和激发碎片分子的激光均为线偏振光 ,而探测荧光为非偏振光 .激光诱导荧光强度是光碎片分子初始态多极矩、线强度因子和解离—激发几何因子的函数 .光碎片的取向参数可以由测量荧光偏振比和计算动力学因子而获得

Theoretical Study of Detecting Photofragment Alignment Using Laser-Induced Fluorescence

Expressions used for extracting the alignment parameter of photofragment from the laser induced fluorescence (LIF) intensity are derived by employing the density matrix approach. The alignment of photofragment is described by molecular state multipoles. Both lasers used to dissociate parent molecule and to excite photofragment are linearly polarized lights. And detection fluorescence is an unpolarized light. The LIF intensity is a function of the initial molecular state multipoles, the line strength factor and the dissociation excitation geometrical factor. The alignment parameter of photofragment can be found by measuring the polarization ritio of fluorescence and calculating the dynamic factors.