Phase screen generation method for general oceanic turbulence

Optical wave propagation through oceanic turbulence suffers from phase and amplitude distortions caused by refractive-index fluctuations due to temperature and salinity random variations in seawater. The split-step method has been widely employed for numerical simulation of light propagation in turbulent media, where the propagation path is discretized into multiple segments. This discretization ensures that each segment is sufficiently short such that refractive-index variations induce only phase distortions without affecting the amplitude. A critical component of this method involves accurate generation of thin phase screens (PSs) based on the refractive-index spatial power-law spectrum (RISPS). This study utilizes the general oceanic turbulence RISPS to create PSs. We show that optimal accuracy requires a hybrid implementation combining PWD (proposed by Paulson, Wu, and Davis) frequency-domain approach with Zernike polynomial-based spatial-domain decomposition.