LAUSR

The Bessel Gauss beam has shown good performance in solving occlusion by the secondary mirror of Cassegrain antenna. In this work, the analytical expression for the optical field of the Bessel Gauss beam after passing through the optical communication system comprising two Cassegrain antennas in atmospheric turbulence is derived. The light filed is obtained more precisely by optimising the parameters of the hard-edged optical aperture. And the energy efficiency of the whole system is investigated more accurately taking into account the efficiency of two antennas and the reflection losses. For the 3 order Bessel Gauss beam, the optimal parameters of the system are obtained by calculation. When b = 0.1m, a = 0.0162 m, ηT of Bessel Gauss beams when l = 1 ∼ 5 are 64%, 91%, 96%, 96%, 96%, respectively. At the same time, the light field expressions we have derived allow us to easily analyze the effect of atmospheric turbulence and antenna defocus on the efficiency of the system. So the effect of turbulent atmosphere and antenna defocus on the efficiency of the system and the corresponding reasons are studied as well.