Wavefront Sensing and Correction via Compressive Sensing and Advanced Photonic Devices

Turbulence-induced wavefront distortion poses a significant obstacle in the implementation of large constellation coherent modulation techniques in optical satellite-to-ground feeder links. The challenging atmospheric conditions of low earth orbit satellite systems, characterized by short coherence times and small spatial coherence widths, necessitate the development of fast and simple wavefront estimation and correction methods. This paper presents an innovative solution to this problem, by proposing a wavefront sensing and correction system that utilizes fast optical phase shifters, optical grating couplers, and compressive sensing techniques to mitigate the effects of turbulence-induced wavefront distortion. Numerical simulations demonstrate that the proposed approach effectively combats wavefront distortion using a small measurement ratio of less than 0.001, where the measurement ratio is the ratio of the number of measurements to the total number of wavefront pixels. In addition, the proposed approach can effectively address phase mismatches between the optical carrier and the local oscillator.