The interest of beams carrying orbital angular momentum (OAM) for free-space optical communication (FSOC) has increased over the years, due to the large number of orthogonal modes which can be used to transmit data at high data rates, and the secure transmission it offers. One of the main concerns in FSOC applications is atmospheric turbulence through which all beams propagate. The atmospheric turbulence is degrading the quality of the laser beam, due to the creation of intensity variances, beam wander, loss of spatial coherence, and OAM cross talk. A wave optics simulation framework is used to model OAM beam propagation through atmospheric turbulence. In these simulations Laguerre-Gaussian (LG) beams are used as beams carrying OAM. The atmospheric turbulence is modeled as phase screens and a split-step algorithm is used to model the beam propagation. LG beams with different mode order are propagated through atmospheric turbulence of different strengths. The results will be compared against experiments performed in the laboratory.
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