A simple analytical model of adaptive optics for direct detection free-space optical communication

A simplified analytical model for the analysis of the performances of an adaptive optics system is described for application to direct detection free-space optical communication in the atmosphere. The transfer function of the adaptive optics control loop is calculated in the Zernike and Fourier domains for temporal and spatial dependence, respectively, and is used to determine the power spectrum of the corrected wavefront. To illustrate the model, an adaptive optics system is studied for the downlink channel of the free-space optical link operated by the European Space Agency between the ARTEMIS satellite and the Optical Ground Station in Tenerife Island, Spain.