Creation of the maximum coherence via adiabatic passage in the four-wave mixing process of coherent anti-Stokes Raman scattering

Abstract

Coherent anti-Stokes Raman scattering has been broadly used as an efficient method for molecular identification and specification, utilizing nonlinear optics response of a medium based on inherent and unique properties of its compounds. CARS implies the four-wave mixing process with three beams incident on the molecules and the fourth generated in the medium as a nonlinear response. Here we present a novel method for optimizing this response by maximizing the vibrational coherence in the target molecules. We demonstrate that all three incident fields must be chirped subject to quantum control conditions in order to achieve adiabatic passage between four states in the CARS scheme leading to a maximum vibrational coherence.