Performance analysis of Sinh and Cosh Gaussian vortex beam in vertical underwater optical communication

Abstract

The performance analysis of Sinh Gaussian vortex beam (ShGvB) and Cosh Gaussian vortex beam (ChGvB) in oceanic turbulence is established by employing an anisotropic spatial power spectrum that considers the influence of the ocean depth to mimic the actual oceanic conditions. Since the salinity and temperature variations along depth are not linear, the actual data of temperature and salinity measured from the tropical region of the ocean is used for the current study. The propagation properties of the ShGvB are studied by deriving the cross-spectral density of the beam, and the average intensity of the beam is plotted over depth and studied in both isotropic and anisotropic oceanic turbulence systems. The analysis of the beam spot radius shows that the beam degrades faster in anisotropic media than in isotropic media. Quantitative estimation of the detection probability, channel capacity and bit error rate (BER) have been made to evaluate the beam's performance for vertical underwater optical communication. The BER may be improved by enlarging the detector aperture radius and signal-to-noise ratio. The ShGvB performs effectively in vertical underwater optical communication compared to the ChGvB.

GRAPHICAL ABSTRACT

KEYWORDS:

• Vortex beam
• oceanic turbulence
• vertical underwater optical communication
• bit error rate
• Sinh Gaussian vortex beam
• anisotropic oceanic turbulence

Acknowledgement

ATD and PG acknowledges for the financial support received from the Defense Research and Development Organization (DRDO), Govt. of India [ERIP/ER/202204002/M01/1798]. ATD wish to thank Joseph Abraham Thomas for useful suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This work was supported by Defence Research and Development Organisation (DRDO), Govt. of India: (Grant Number ERIP/ER/202204002/M01/1798).