Nonlinear circular dichroism in a liquid of chiral molecules

Summary form only given. Nonlinear optical properties of chiral molecules have been studied for a few years by surface second harmonic generation, but no experimental work has been carried out about third order processes. Processes such as pump/probe experiments are known to be an efficient means to investigate the electronic properties of molecules as well as their dynamics, but these techniques have never been utilized to probe chiral molecules. We investigate the signature of optical activity in the third order nonlinear response of an isotropic liquid of chiral molecules. We first perform a general calculation which formally evidences the existence of a nonlinear circular dichroism. Then, utilizing simple classical calculations based on anharmonic oscillators in the Kuhn or Kauzmann models, we investigate more carefully the impact of the origin of the optical activity on a pump/probe experiment.