Hybrid four-wave mixing in liquid pyridine

Abstract

Four-wave mixing spectra for liquid pyridine are obtained with broadband laser beam. A comparison of Stokes and anti-Stokes spectra allows the assignment of several lines (951, 991, 1030 cm −1) to CARS and CSRS processes. Two additional moderately intense lines on the Stokes side between 951 and 991 cm −1 as well as 991 and 1030 cm −1 , which do not appear on the anti-Stokes side, are assigned to a “hybrid four-wave mixing” process, in which two active Raman modes of pyridine are involved. This process previously unrevealed in experiment seems to be important for correct assignment of the spectral lines in four-wave mixing experiments with a broadband laser beam.