Fast dynamic correction algorithm for model-based wavefront sensorless adaptive optics in extended objects imaging

A major concern for wavefront sensorless adaptive optics (WFSless AO) is how to improve the algorithm's efficiency which is critical for dynamic aberration correction. For extended objects and dynamic aberration, a typical model-based WFSless AO algorithm is called "3N" which uses three image measurements to estimate each aberration mode and then corrects it immediately. The three images include an initial aberrated image and two biased images with deliberately introduced predetermined positive or negative modal aberrations. In this paper, an improved algorithm called "2N" that requires only one biased image is proposed. The reduction of one biased image is achieved by the estimation of a parameter that is considered unknown in the 3N algorithm. It is demonstrated that the 2N algorithm can achieve convergence with less image measurements and have better performance in dynamic correction. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement