Effectiveness of adaptive optics for coherent laser communications in atmospheric turbulence

We theoretically investigate how adaptive optics (AO) can reduce symbol error probability (SEP) of free-space optical communications systems based on phase-shift keying heterodyne coherent receivers. In our analysis we use an updated model for describing the optical turbulence-induced fading present in coherent communications systems and it is assumed that AO is implemented at the receiver side. We consider the ideal case of partial phase conjugation, or in other words, we assume that the Zernike modes (up to the specific number Nmodes) can be corrected with 100% accuracy. Results show that removal of several modes from the turbulence-affected wavefront allows to reach values of SEP that are typically required in coherent laser communications.