Effects of spatial interference on intensity--intensity correlations in collective two-atom emission

In this paper, we investigate the effects of the spatial variation of driving-laser phase in a collective two-atom system on the intensity–intensity correlations of the resonant fluorescence. It is shown that the intensity–intensity correlations exhibit quite different characteristics for the different values of the spatial phase of the laser at the position of the two atoms in both cases of the weak and strong driving lasers. Our results suggest that the intensity–intensity correlations can serve as a probe of the spatial interference effect arising from the spatial variation of the laser phase.