Propagation properties and spatial-mode UWOC performance of quasi-perfect optical vortex beam in an improved oceanic channel

Abstract

In this study, the Quasi-perfect optical vortex (Quasi-POV) beam with topological charge-independence radial distribution is investigated to enhance the performance of underwater wireless optical communication (UWOC) system based on spatial modes. Additionally, the oceanic channel model is modified to obtain more reliable simulation results. The propagation and communication performance of perfect optical vortex (POV) beam and Quasi-POV beam are compared and analyzed through the modified model. With the optimization of beam’s parameters, Quasi-POV beam achieves lower bit-error rate (BER) and higher average capacity in multiple phase shift keying (M−PSK) modulated UWOC system. The results indicate that Quasi-POV beam receives higher normalized intensity and lower crosstalk probability than the POV beam, the average simulation results for the three topologic charge cases show that the BER of Quasi-POV beam at 100 m reduced by approximately 52%, the average capacity of Quasi-POV beam increased by approximately 13.3%. The Quasi-POV beam has better performance than the POV beam in Spatial-Mode UWOC system according to the simulation results, which is more suitable for UWOC system based on spatial modes with smaller values of topologic charge.