A broadband multiplex CARS system for accurate Raman depolarization ratio measurements has been constructed. By precisely controlling the directions of polarization of the two incident laser beams and detecting a particular polarization component of the CARS signal, this system can determine Raman depolarization ratios of liquids accurately to the order of 0.001. We measure a number of polarized CARS spectra with different polarizer settings (polarization- resolved CARS spectroscopy) and simulate the resultant change of band shapes to determine the depolarization rations. Polarizationresolved CARS spectroscopy has become feasible only by virtue of the highly efficient broad band multiplex technique. Cyclohexane, 1,2-dichloroethane, and the sulfate ion have been investigated to test the performance of the system.
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