Fast and scintillation-resistant wavefront sensing for laser applications

Propagating lasers through strong turbulence presents unique challenges that differ significantly from those of astronomical adaptive optics (AO). Therefore, unconventional approaches must be developed to meet these requirements. At Fraunhofer IOSB, several wavefront sensing concepts have either been invented or further developed for this purpose. Our work has focused on wavefront sensors (WFS) suitable for monochromatic light, i.e. lasers, and on achieving the highest possible bandwidth, as these sensors are primarily used for laser-based communications and energy delivery to and from fast- moving aircraft or satellites. This paper focuses on three such sensors: the holographic WFS, the angular selective WFS, and the heterodyne WFS. Using the Python High-Fidelity Wave-Adaptive-Optics Simulator (PHWAOS), we demonstrate that the heterodyne WFS remains effective in a closed-loop system under strong scintillation during low-elevation observations, whereas the Shack–Hartmann sensor fails.