Analysis and Optimization of Bit Error Rate for Double-Ring Perfect Optical Vortex Beam in Oceanic Turbulence

The double-ring perfect optical vortex (DRPOV) beam offers more intensity patterns and controllable parameters than the traditional signal-ring perfect vortex. In this study, we investigate the bit error rate (BER) performance of a DRPOV beam in oceanic turbulence. A theoretical model for analysis is established based on the unstably stratified turbulence spectrum and quadrature amplitude modulation format. The results indicate that the two auto-focusing processes of DRPOV beam help to mitigate turbulence effects and improve BER performance over a wide propagation range. The auto-focusing behaviors are adjustable by double-ring structural parameters to adapt to different scenarios. In order to reduce BER, the increments of outer-ring intensity weight and overall beam size are preferred for long-range propagation, while the opposite sets are preferred for short distance. The position corresponding to the local BER minimum is controllable. In addition, the lower-order signal modulation with longer wavelength also achieves a lower BER. The research provides a reference for information transmission using vortex beams.