Fluctuations of laser radiation intensity reflected from a turbulent atmosphere

The Huygens–Fresnel principle is generalized to the case of smoothly inhomogeneous media and applied to the problem of diffraction of a laser beam by a reflector of finite dimensions. A numerical analysis is reported of the influence of an atmospheric turbulence on the variance and spatial correlation function of the intensity fluctuations in the diffracted field. It is shown that the principal features of the intensity fluctuations in a reflected beam are basically the same as in direct propagation.