Superradiant Intensity Fluctuations

We describe a new approach to the problem of superradiant spontaneous emission, which is applicable whether the number of atoms is large or small. We use this approach to formulate intensity correlations of arbitrary order, and then explicitly evaluate the second-order normally ordered relative intensity fluctuation. Large fluctuations at the onset of emission indicate the discrete nature of the spontaneous emission process; and the very small fluctuations found later at the emission peak show that the emitting process has by then become essentially classical.