Abstract
The effect of cooperative atomic interactions on the photon statistics in a single-mode laser is studied on the basis of an equation of motion for the reduced-density operator of the field that was recently derived by Huang and Mandel. The corresponding antinormal ordering distribution function is shown to satisfy a Fokker-Planck equation. The steady-state solution of this equation is used to determine the photon-number distribution, the average intensity, and the intensity fluctuation.