Work

Intensity–phase–modal degradation of Bessel–Gaussian vortex beams in sea-fog scattering environments

Year: 2026

Type: article

Abstract: Finite-energy Bessel–Gaussian (BG) vortex beams are investigated in controlled sea-fog scattering environments to clarify their intensity, phase, and modal degradation mechanisms. An intensity-scattering and phase-equivalent evolution model is established using Mie scattering theory and orbital-angular-momentum (OAM) spiral-spectrum expansion. Salt-fog environments are generated by atomizing saline solutions with nominal sea-salt mass fractions of 1.5 wt.% and 3.5 wt.%, and four optical thicknesses are calibrated by transmittance measurements. Simulations and experiments show that sea fog induces not only energy attenuation, but also annular-structure blurring, dark-core filling, helical-phase distortion, and OAM modal crosstalk. At τ =2.071 for salt fog generated from the 3.5 wt.% saline solution, the original mode remains dominant in the modal spectrum, although its modal purity is reduced and energy leakage to neighboring modes becomes more evident.

Source: Optics Express

DOI: 10.1364/oe.609737