Optical communications are described and analyzed by shaped beams; we challenge the effects of parameters that impact the profile of a Flat Top Gaussian (FTG) beam. When the laser beam propagates throughout the atmosphere, it can be influenced by different optical phenomena including scattering, absorption, and turbulence due to changes in the scintillation index and the forms of intensity that are displayed in the source and receiver planes. In this project, the FTG laser beam that propagates through a weak turbulent region is numerically investigated using open-source software. This simulation will be performed according to a mathematical model based on the split-step beam propagation method. Intensity distributions at the source plane and the received average intensity in atmospheric turbulence are calculated, and additional contour is in the transducer plane. The scintillation index, structure constant, source size, and other parameters, are applied in the Rytov method to quantify the weak turbulent model. Moreover, these parameters are analyzed in near-field propagation. Also, the effects of the beam’s scintillation and beam wander are determined. All results simulated are discussed and compared with the TEM00 Gaussian beam. Finally, these results are compared to measurements in the experimental part of the work.