Theoretical Foundations for a New Family of Infrared Four-Wave Mixing Spectroscopies

Abstract

A new family of selective four-wave mixing methods, based on the establishment of vibrational nonlinear polarizations with multiple resonances, is proposed. This family includes double-infrared resonances, vibrationally enhanced Raman resonance, and vibrationally enhanced two-photon resonance. These methods are related to traditional Raman and infrared spectroscopy, but the methods are shown to have the capabilities for component and conformer selectivity, line-narrowing of inhomogeneously broadened vibrational transitions, and mode selection. The theoretical foundations for the methods are developed and directed to possible applications.