Coherent Raman Spectroscopy of Molecular Clusters

尼布勒教授得到了实验物理化学项目的支持，继续研究用非线性光学技术探测的分子团簇的性质。这项工作涵盖了从二聚体到更大的团簇的大小范围，并解决了从二聚体结构和光谱性质到研究较大凝析油的成核、生长以及表面和整体性质的一系列问题。利用受激拉曼散射和相干反斯托克斯拉曼散射，在距自由喷流膨胀源喷嘴不同的距离处，探测了氮、氧、氢、二氧化碳和乙炔等大分子团簇。振动光谱和纯转动光谱都在产生，产生了关于团簇膨胀和凝聚过程的演化信息。氮、氧和氢二聚体的拉曼探测工作仍在继续；这些都是重要的二聚体，它们的对称中心使它们无法通过光谱进行探测，除非使用拉曼技术。

Professor Nibler is supported by the Experimental Physical Chemistry Program in a continuing investigation of the properties of molecular clusters probed by nonlinear optical techniques. The work spans the size range from dimers to much larger clusters and addresses issues ranging from dimer structure and spectroscopic properties to the study of nucleation, growth, and surface and bulk properties of larger condensates. Large clusters of molecules, such as nitrogen, oxygen, hydrogen, carbon dioxide, and acetylene, are being probed by stimulated Raman scattering and coherent antistokes Raman scattering at various distances from the source nozzle of a free jet expansion. Both vibrational and pure rotational spectra are being produced, yielding information on the evolution of the cluster expansion and the condensation processes occuring. Work continues on Raman probing of dimers of nitrogen, oxygen, and hydrogen; these are important dimers whose centers of symmetry make them inaccessible spectroscopically except through use of Raman techniques.