Sum-frequency vibrational spectroscopy on molecular chirality

Summary form only given. We report the observation of the first sum-frequency vibrational spectra from a number of chiral liquids. The results are related to the influence of local chiral structure on selected atomic groups of the molecules. We shall focus our discussion on chiral liquids of limonene, which is a relatively small molecule with a simple chiral structure. Using appropriate input/output polarization combinations, we can selectively probe only the chiral component of the nonlinear optical susceptibility. We observe a clear circular dichroic response from the enantiomers of limonene in the CH stretch vibrations.