Interference of third-order light mixing and second-harmonic exciton generation in CuCl

Abstract

The generation of the combination frequency $2{\ensuremath{\omega}}_{1}\ensuremath{-}{\ensuremath{\omega}}_{2}$ in CuCl by two incident waves, at frequencies ${\ensuremath{\omega}}_{1}$ and ${\ensuremath{\omega}}_{2}$, respectively, is measured as a function of ${\ensuremath{\omega}}_{1}$. When $2{\ensuremath{\omega}}_{1}$ equals the frequency of the first longitudinal-exciton resonance, a resonant dispersive behavior in the production of the intensity at $2{\ensuremath{\omega}}_{1}\ensuremath{-}{\ensuremath{\omega}}_{2}$ is observed.