Structure Functions in Turbulence for Incidence With Arbitrary-Field Distribution

Abstract

In a turbulent atmosphere, the log-amplitude, phase-correlation, and structure functions are formulated for light sources exhibiting arbitrary-field distribution. This is done by extending the formulations of the correlation and structure functions for the known general-type beam sources to cover any type of source having arbitrary-field distribution. To introduce the arbitrary field, the source is presented by an incidence that is a function of transverse source coordinates. The received field in the random medium is found by employing the Rytov method, which is a single-scattering solution obtained by the first-order approximation; thus our results are valid in weak turbulence. All the existing results can be correctly reproduced from our formulations when the corresponding source-field distributions are inserted into our presented correlation and structure-function expressions. Our results for the arbitrary-source field profiles can be utilized in finding the scintillation index and the angle-of-arrival fluctuations of any type of incidence in optical atmospheric links. Additionally, our formulations can find applications in reflection from rough surfaces and imaging in turbulence. (C) 2007 Optical Society of America