Probability density of irradiance for optical waves propagating underwater in the presence of air bubbles

Abstract

SummaryThe use of wireless optical waves could prove valuable to numerous underwater applications compared to radio frequency and acoustic waves. However, optical signals are susceptible to attenuations and scintillation (fading) due to the turbulent nature of underwater environments. Therefore, it is imperative to determine the wave intensity distribution. General approach to this problem is to apply existing atmospheric propagation models or to device a statistical distribution based on experimental data. Recent studies show that the well‐known probability density functions poorly describe EM optical wave propagation underwater in the presence of air bubbles, and thus, mixture distributions were proposed. This, however, ignores the physical aspects of the phenomena, and as such may limit the model region of validity. In this paper, a novel intensity distribution model is derived based on the Rytov theory of propagation through weak turbulence. Furthermore, the distribution is validated by experimental data over a large range of turbulence levels.