Fluctuation experiments on atomic and molecular systems using the one-atom detector

Fluctuation studies of atomic molecular populations have been made by means of one-atom detection techniques. Density fluctuations of atoms and density fluctuations of molecules, as well as photoionization yield, photodissociation yield, and collisional broadening fluctuations, were studied, using appropriate laser saturation conditions. In each case it was found that the Poisson distribution described the observed frequency distributions, suggesting that the underlying assumption of random behavior is valid for all five of these physical phenomena.