Scrutinizing the effects of turbulence on partially coherent Gaussian beam propagating through Caspian Sea

Abstract

In this paper, the total attenuation due to scattering, absorption and turbulence is considered in investigation of link parameters of the underwater horizontal optical communication system in the Caspian sea. In the present paper, based on extended Huygens-Fresnel principle and the unified theory of coherence and polarization, analytical formulas for Cross-Spectral Density (CSD) matrix elements and the Spectral Degree of Polarization (SDP) are derived. By using the matrix elements of cross-spectral density, some valuable analytical expression for defining Power In Bucket (PIB), Signal to Noise Ratio (SNR) and Bit Error Rate (BER) are presented. Then, the effects of some source and turbulent ocean factors on link parameters of partially coherent Gaussian beam propagating through turbulent water are scrutinized. It is deduced that underwater communication link parameters are affected by environment’s factors (e.g. Chlorophyll concentration (CC), turbulence parameters) and source parameters (e.g. laser wavelength). Investigating spectral degree of polarization shows that by increasing the strength of oceanic turbulence, the fluctuation of spectral degree of polarization becomes smaller. The obtained results are displayed with graphs.