Abstract

The non-Gaussian nature of optical wave scattering by a number of different mechanisms has been modeled as a compound random modulation process. The success of this modeling approach has been due to the scattering mechanisms themselves having two discernible scales of fluctuations. A small-scale fluctuation appears to have a modulation over a much larger scale. This modulated scatterer gives rise to a similar scattered optical wave. The scattered optical wave appears to have a fine structure whose strength is modulated by a more coarse structure. The probability density function (PDF) of the detected intensity can be calculated from conditional statistics. The small-scale rapid fluctuations are treated as a conditional PDF and then averaged over the PDF of the large-scale slower fluctuations. This approach has been used to describe scattering by surfaces, phase screens, and extended path turbulence. A more exact approach to this two-scale phenomenon is to express the scattered field as a sum of scattered components, i.e.,

© 1988 Optical Society of America