Complex Raman amplitude recovery and dynamics from the Raman excitation profile: application to iodobenzene and azulene
Complex Raman amplitude recovery and dynamics from the Raman excitation profile: application to iodobenzene and azulene
复制标题
拉曼激发曲线的复杂拉曼振幅恢复和动力学：在碘苯和甘菊环中的应用
DOI：
10.1002/jrs.718
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发表时间：
2001
影响因子：
2.5
通讯作者：
Soo
中科院分区：
文献类型：
--
作者：
Z. Feng;Soo
从强度恢复复振幅或相位是不同物理区域共同的问题，所述强度被给出为振幅的模平方。本文的重点是拉曼激发分布-作为激发能量的函数的模式的拉曼强度-这是由拉曼振幅的模平方。三种方法，具有不同的原则，幅度或相位恢复：色散或能量帧的方法，z变换或时间帧的方法，和最大熵的方法。一个比较函数技术被引入到解决通常的情况下，测量的强度是带限的。存在两类问题，最小相位和非最小相位，并且从强度到复振幅的映射可能不是唯一的。非最小相位的情况发生在解析扩展的复振幅，其中能量E被替换为γ = γ − iE，在右半复平面中为零。这些零点对系统动力学有影响。提出了一种寻找临界零点的算法。用双模谐波模型研究了零点的特性，并将理论应用于碘苯和甘菊环的拉曼激发谱。版权所有© 2001约翰威利父子有限公司。
Recovering the complex amplitude or phase from an intensity, which is given as the modulus square of the amplitude, is a problem common to diverse physical areas. The focus of this paper is on the Raman excitation profile — the Raman intensity of a mode as a function of the excitation energy — which is given by the modulus square of the Raman amplitude. Three methods, with different principles, are presented for amplitude or phase recovery: the dispersion or energy-frame method; the z-transform or time-frame method; and the maximum entropy method. A comparison function technique is introduced to address the usual situation where the measured intensity is band-limited. There are two classes of problems, minimum phase and non-minimum phase, and the mapping from the intensity to the complex amplitude may not be unique. The non-minimum phase situation occurs when the analytically extended complex amplitude, with the energy E replaced by ξ = γ − iE, has zeros in the right-half complex plane. These zeros have implications for the system dynamics. An algorithm is presented to search for the critical zeros. The characteristics of the zeros are studied with a two-mode harmonic model, and the theory is applied to the Raman excitation profiles of iodobenzene and azulene. Copyright © 2001 John Wiley & Sons, Ltd.