Spatial-energy characteristics of a focused laser beam with random phase distortions of the field inside an unstable resonator

The correlation function of laser output radiation is theoretically investigated depending on the statistical characteristics of the random phase distortions of the field inside the unstable resonator. The intracavity field is considered in the optico-geometric approximation. In the Fresnel approximation, the distribution function of the radiation flux for a focused laser beam is studied.