Abstract

Investigation of the intensity correlation properties of laser radiation propagating in the lower atmosphere is of great importance in constructing laser communication and surveillance systems. Significant effort in theoretical research is concentrated on obtaining approximate analytical and numerical solutions for the fourth-order statistical moment of the high frequency random field propagating in a weakly fluctuating medium. Most of the numerical results deal with infinite plane wave excitations, and there are very few results for finite aperture fields. One of the powerful analytical methods allowing one to obtain explicit analytical expressions for the fourth-order statistical moment is the two-scale expansion procedure. These solutions are expressed in a multiple integral form and their computations are in good agreement with the numerical solutions of the fourth-order moment equation for a plane wave initial excitation. However in the finite beam case, the number of the integrations increases and the numerical evaluation of the solutions requires considerable computational resources.

© 1989 Optical Society of America