Accurate Wavefront Correction With Partial Slope Information of Shack-Hartmann WFS

In this letter, we report a weighted modal wavefront control method for surmounting the problems of sub-aperture spot missing in Shack-Hartmann wavefront sensors (SHWFS) and the resultant unstable wavefront control. This method supplements the slope information of sub-apertures lacking spots through the modal method, in which the suppression method of model aliasing is proposed to correct inaccurate slope estimates. In this process, an iterative preprocessing method is used to improve the speed of equation solving. Finally, we verified the effectiveness of this method through experiments, and the experimental results showed that when the proportion of sub-apertures lacking spots reaches 60%, the encircled energy Strehl ratio of the corrected far-field spot can still reach 0.8.