Wireless optical wave propagation in underwater medium

In this thesis, the effects of the turbulence on the average transmittance are examined when the lowest order collimated Gaussian optical beam wave propagates in a wireless underwater medium. To observe the oceanic turbulence effect, the power spectrum of homogeneous and isotropic oceanic water combining the effects of salinity and temperature is used. Employing the Rytov method and the numeric integration, the effects of the parameters of power spectrum on the average transmittance are analyzed. Obtaining results with the help of Matlab program indicates that the rate of dissipation of the kinetic energy per unit mass of fluid is directly proportional to the average transmittance while the rate of dissipation of the mean-squared temperature is inversely proportional to the average transmittance. Increase in the link distance and decrease in the wavelength reduce the average transmittance. When the temperature-induced optical turbulence is dominant in the ratio of the salinity and temperature contributions to the refractive index spectrum, the average transmittance almost never decreases. However, the salinity-induced optical turbulence reduces the average transmittance sharply. Increasing the Kolmogorov microscale length, first the turbulence effect increases and the average transmittance decreases, but when the value of Kolmogorov microscale is further increased, the turbulence effect starts to decrease and the average transmittance increases, eventually a saturation is observed.