Strehl ratio and spread rate of Gaussian-Schell model beams in the marine-atmosphere link of weak to strong scintillations

We present the models of the Strehl ratio (SR) and the spread rate of Gaussian-Schell model (GSM) beams in the long slant path of marine-atmosphere turbulence. The models are developed based on the extended Rytov theory which permits us extending the results of weak scintillation into the moderate-to-strong scintillation regimes. Our results show that there exists a minimum of SR for selected waist radiuses and the minimum SR is dependent on the transverse coherent width of light source. The spread rate increases with increasing the light wavelength but it decreases with increasing the waist radius and the inner scale. The effects of turbulence on the peak received irradiance can be reduced by selecting larger waist radius of transmitting aperture and longer light wavelength.