Stochastic field-induced nonlocal resonances in four-wave mixing - art. no. 063806

We explore theoretically the signal generated by a fluctuating radiation fi eld via a four-wave mixing process in an atomic vapor undergoing Markovian dephasing collisions. We consider specifically a broadband laser field well detuned from the atomic resonance and calculate the signal generated using counterpropagating pump fields as a function of the time delay of the inci dent probe field. We assume that the pulse duration is long compared to the correlation time of the incident fields. By considering the various time-o rdered pathways and treating the incident-field amplitudes as random Gaussi an variables, we find that the signal generated is dominated by two specifi c pathways that depend only on the incident-field bandwidth and the decay r ate of the ground to excited state coherence. An interesting aspect of the far-impact-detuning case is that the signal is dominated by resonances invo lving spatially separated atoms. Our formalism provides a basis for describ ing the effects of mode correlations on four-wave-mixing signals generated by stochastic fields.