Speckle-based adaptation concept of a compensation system for free-space optical communications

Abstract

The first practical step in resolving the turbulence issue in satellite-to-earth laser communications has been the use of conventional adaptive optics systems. The concept of a modal iterative approach is presented in this study, which combines some of the characteristics of the indirect methods outlined. This allows for a significant decrease in the loop bandwidth consumption throughout the iterative process. With the assumption that each speckle may be Fourier linked to the pupil plane, which has a plane wave mode, this approach employs discrete speckles from a single image with a short exposure intensity. The approach is described, together with the general mathematical background. In the end, this work presents a numerical analysis of the approach performance estimate in a turbulent satellite downlink scenario.