The optical intensity distribution in the far field

This article describes an intensity distribution of optical beam in the far field. In free space communication laser transmitters, optical lenses and other components are used. When an optical beam impacts optical lens, the diffraction can appear at the edge of lens. A laser transmitted optical beam whose intensity distribution was Gaussian. This beam was aimed at the circular apertures of different diameters. These circular apertures represented transmitting lens. We could use circular apertures instead of lenses, because we obtained the same effects of diffraction. The optical beam passed by aperture and optical intensity distribution was observed at the screen, which was placed in the far field.