  We present a theoretical analysis of the intensity autocorrelation for the
spontaneous emission from a planar ensemble of self-assembled quantum dots.
Using the quantum jump approach, we numerically simulate the evolution of the
system and construct photon-photon delay time statistics that approximates the
second order correlation function of the field. The form of this correlation
function in the case of collective emission from a highly homogeneous ensemble
qualitatively differs form that characterizing an ensemble of independent
emitters (inhomogeneous ensemble of uncoupled dots). The signatures of
collective emission in the intensity correlations are observed also in the case
of an inhomogeneous but sufficiently strongly coupled ensemble. Thus, we show
that the second order correlation function of the emitted field provides a
sensitive test of cooperative effects.
