The Mandel probability distribution of one-mode stochastic radiation photocounts is analized. Approximations of n-photon registration probabilities with guaranteed accuracy are obtained in the case when the registration time is sufficiently small.
We derive a closed-form expression for the number probability distribution of a ``generic'' two-mode field in a two-mode squeezed state. We discuss its dependence on the average particle number in the two modes and on the amount of squeezing. We show that the distribution exhibits oscillations for particle numbers appropriately greater than the average, similar to the one-mode case, although the conditions under which such an oscillatory behavior occurs are different. These results are directed to the investigation of nonclassical properties in the radiation field produced by a parametric amplifier operated in a two-mode regime.
Exact photocounting distributions are obtained for a pulse of light whose intensity is exponentially decaying in time, when the underlying photon statistics are Poisson. It is assumed that the starting time for the sampling interval (which is of arbitrary duration) is uniformly distributed. The probability of registering n counts in the fixed time T is given in terms of the incomplete gamma function for n >/= 1 and in terms of the exponential integral for n = 0. Simple closed-form expressions are obtained for the count mean and variance. The results are expected to be of interest in certain studies involving spontaneous emission, radiation damage in solids, and nuclear counting. They will also be useful in neurobiology and psychophysics, since habituation and sensitization processes may sometimes be characterized by the same stochastic model.