Modelling the interaction of structured light in turbulent environments through statistical interpolation of computational fluid dynamic phase screens

Atmospheric turbulence causes time-varying optical density changes along free-space optical (FSO) links, leading to distortions in a beam’s propagation. Traditional statistical models, like the Kolmogorov or Von-Karman power spectral densities, assume homogeneous and isotropic turbulence, which is often not valid in urban environments with localized heat sources and varying landscapes. Structured light is particularly affected by such volumetric turbulence, and existing metrics do not adequately represent these effects, complicating the identification of correction techniques. This work introduces a novel modeling method that uses large-eddy simulations (LES) from computational fluid dynamics (CFD) to capture low-frequency turbulence structures and combines them with statistically representative high-frequency components. The approach allows for the simulation of structured light distortions in various deployment scenarios, enabling performance estimation of FSO communication, imaging, and sensing systems without costly field trials, thus offering a more efficient alternative to conventional methods.