Influence of coherent properties of an optical field on the photocount statistics

The asymmetry of photocount statistics in respect of the spatial and temporal coherence factors is demonstrated and explained. This asymmetry appears because of the "dead time" of a counter receiving a non-Poisson photoelectron flux. A statistical model of an optical field, photoelectron flux, and counting flux is used in a computer study of the dependences of the distributions and moments of the number of counts in a given time interval on the ratio of the coherence factors. An explanation of the features of these dependences is provided. A determination is made of the range of conditions in which the asymmetry is significant. In particular, the asymmetry disappears in the case of a Poisson photoelectron flux and for a very short dead time.