Research on the transmission properties of vortex beams in fog based on a model of random particle screens

Vortex beams, with their unique structure carrying orbital angular momentum, demonstrate significant potential in laser detection, imaging, and optical communications. However, their transmission performance in foggy environments is affected by scattering effects. In this paper, we propose a model of random particle screens based on Mie scattering theory to simulate the propagation of vortex beams in fog. We systematically investigated the influence of topological charge ( l ), transmission distance, fog visibility, and waist radius on the transmission characteristics of vortex beams, quantitatively evaluating signal quality using the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). The beam expansion effect associated with l and the increase in beam waist radius both led to enlarged interaction area between the vortex beams and fog medium, resulting in degradation of both PSNR and SSIM. Notably, larger beam waist radius caused faster deterioration of SSIM. Reduced visibility and longer transmission distance intensified cumulative scattering effects, collectively degrading both PSNR and SSIM. When the transmission distance was shorter than fog visibility, lower-order vortex beams exhibited better stability compared to higher-order beams. As l increased, SSIM declined more gradually than PSNR. However, with further increases in transmission distance, SSIM became more sensitive to variations in l . This study provides theoretical and simulation-based insights for designing vortex beam based free-space optical communication systems and harsh-environment detection applications. Furthermore, it provides support for future research on multimode multiplexing and intelligent scattering suppression algorithms.