Numerical study of centroid detection accuracy for Shack-Hartmann wavefront sensor

It is crucial for the wavefront sensor to reduce the influence of noise and enhance the detection accuracy of the centroid, which is also an important step for improving the performances of adaptive optics. In this paper, based on the theoretical analysis and by utilizing the Monte-Carlo simulation (MCS) technology, the results obtained by using the centroid algorithms have been compared in detail for the case, in which centroid of the signal is not at the center of the detection area and it also has a relatively large area. It is shown that the size of the signal spot and its centroid position have considerable influences on the centroid detection accuracy. The numerical results agree well with the theoretical predictions and the optimized parameters for each algorithm have been found. The study will be helpful for further optimizing the optical system and improving the centroid measurement accuracy of the wavefront sensor.