A robust continuous-time multi-dithering technique for laser communications using adaptive optics

A robust system architecture to achieve optical coherency in multiple-beam free-space laser communication links with adaptive optics is introduced. It is based on deterministic multi-dithering and gradient descent flows and accounts for phase delays in the dither signal, during propagation in the atmosphere, as well as saturation of the optical phase shifters. The architecture has been mathematically analyzed and simulation results of a VLSI implementation of the architecture are presented and found in agreement with the theoretical model