Dynamics of atom-mediated photon-photon scattering - art. no. 043819

The mediated photon-photon interaction due to the resonant Kerr nonlinearit y in an inhomogeneously broadened atomic vapor is considered. The time scal e for photon-photon scattering is found to be determined by the inhomogeneo us broadening and the magnitude of the momentum transfer. This time can be shorter than the atomic relaxation time. Effects of atom statistics are inc luded and the special case of small-angle scattering is considered. In the latter case, the time scale of the nonlinear response remains fast, even th ough the linear response slows as the inverse of the momentum transfer. Mea surements of temporal and angular correlations show good agreement with the ory.