A photon counting experiment for student physics laboratory is describ
ed. It is designed to illustrate the probabilistic nature of the photo
detection process itself as well as statistical fluctuations of light.
The setup enables the student to measure photon count distributions f
or both coherent and pseudothermal light sources yielding Poisson and
Bose-Einstein distributions, respectively. (C) 1996 American Associati
on of Physics Teachers.