Garrett-Roe Sean, Hamm Peter
Physikalish-Chemisches Institut, Universität Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
J Chem Phys. 2009 Apr 28;130(16):164510. doi: 10.1063/1.3122982.
We demonstrate a method to collect purely absorptive three-dimensional (3D) fifth-order vibrational spectra on the model system CO(2) in H(2)O. The six beam interferometer is described, as well as a method to experimentally determine the phase of the 3D spectrum. The measured spectra agree very well with simulations of the data based on the cumulant expansion. There are five peaks corresponding to different paths up and down the vibrational ladder. The positions, signs, and amplitudes of the peaks agree with theoretical predictions, and the intensities of the peaks scale linearly with concentration. Based on the concentration dependence and agreement between the simulations and measurements, we conclude that cascaded lower order signals contribute negligibly to the observed signal.
我们展示了一种在H₂O中的CO₂模型系统上收集纯吸收性三维（3D）五阶振动光谱的方法。描述了六光束干涉仪以及实验确定3D光谱相位的方法。测量的光谱与基于累积量展开的数据模拟非常吻合。有五个峰对应于振动能级上上下下的不同路径。这些峰的位置、符号和幅度与理论预测相符，并且峰的强度与浓度呈线性比例关系。基于浓度依赖性以及模拟与测量之间的一致性，我们得出结论，级联的低阶信号对观察到的信号贡献可忽略不计。
