Polarization selectivity of nonresonant spectroscopies in isotropic media

Abstract

We present an analysis of the contributions of the first- and second-derivative tensors of the many-body polarizability to third- and fifth-order nonresonant spectroscopies in isotropic media. Collision-induced effects are shown to have a notable influence on the second-derivative polarizability tensor (Π(2)) for intermolecular modes. As a result, polarization selectivity in nonresonant intermolecular spectroscopies can be achieved in fifth-order spectroscopies. Additionally, terms in fifth-order spectroscopy that arise from three interactions through Π(2) may not be negligible in many liquids. Our analysis shows that there exists no straightforward relationship between the observables in third- and fifth-order intermolecular spectroscopies. The predictions of this analysis are tested against the available experimental data for CS2.