Propagation of flattened Gaussian beams in the atmosphere: a comparison of theory with a computer simulation model

In an attempt to mitigate the effects of the atmosphere on the coherence of a laser beam, interest has recently been shown in changing the beam shape to determine if a different power distribution at the transmitter will reduce the effects of the random fluctuations in the refractive index. We develop a model for the scintillation index of a flattened Gaussian beam and compare this with that of the standard TEM00 Gaussian beam. We verify our results by comparison with a computer simulated model for the flattened beam.