Optical bistability and switching dynamics in an exciton-biexciton model for CuCl

The dynamical evolution of the electromagnetic field amplitudes is numerically calculated using an exciton-biexciton model of CuCl. For a bistable system we determine the switch-down and switch-up times and find them to be well explained by the polariton escape time using the group velocity for the polaritons. Our switching times, about 80 psec at photon energies of 3177 meV, are at least an order of magnitude larger than a previous theoretical estimate and we predict the switching times will become longer as the exciton resonance is approached.