双原子分子光谱

1、 双原子分子光谱Diatomic Molecular SpectroscopyThe Spectra and Dynamics of Diatomic Molecules马维光马维光量子光学与光量子器件国家重点实验室量子光学与光量子器件国家重点实验室山西大学物理电子工程学院山西大学物理电子工程学院激光光谱研究室激光光谱研究室（五）（五）Previous chapter: possible energy levels and symmetries of wavefuncitonThis chapter: interpretation of molecular spectra and invest

2、igation of molecular structureselection rulestransition intensityEinstein definition and quantum definition Putting Dik to a matrix indicating all the possible transitions.Same electronic statesDifferent electronic states(a)(b)line positions and intensities term value and matrix elements:transitions

3、 within the same electronic stateMatrix element:Vibrational transitionRotational transitionTaylor seiresE along z direction polarization All rotational lines for a vibrational transition is called a vibrational band An optical transition between two electronic states occurs so quickly that neither t

4、he positions nor the velocities of the nuclei change significantly during the transition.The electronic transition occurs vertically in the potencial energy diagram -Frank Condon principleSeparate energy (bond state) line spectraMatrix elementsMulti photon probability多光子过程的优点和特征：多光子过程的优点和特征：1、可以跃迁到单光子不能达到的能级；2、利用可见光产生高激发态分子；3、多光子过程增加自电离态的几率；4、可以诱导化学反应；5、利用不同的激光束结构，实现亚多普勒光谱。Rayleigh scatteringInfrared spectraRaman scatteringStockes waves and