The Dynamics of the Transverse Optical Flux in Random Media

Abstract: We study the evolution of the kinetic energy (or gradient norm) of an incident linearly polarised monochromatic wave propagating in correlated random media. We explore the optical flux transverse to the mean Poynting flux at the paraxial-nonparaxial (vectorial) transition along with vortex counting and identify universal features in the dynamics. The vortex number appears to increase with a cubic root for sufficiently small correlation length. Furthermore, a kink appears in nucleation rate at the position of maximum scintillation upon increasing correlation length. A driven steady state is reached due to the filtering of evanescent waves upon propagation. Finally, we present the spectrum of the incompressible kinetic energy and how it evolves from the paraxial case to that of a random field.