Enlarge the dynamic range of Shack-Hartmann Wavefront sensor based on biplanar image acquisition and segmentation methods.

A typical SHWS has a limited dynamic range, which is determined by the f-number of the micro-lens. This causes the spot corresponding to the sub-aperture of the micro-lens to shift out of the corresponding range of the sub-aperture. In this paper, we propose a simple and robust method based on biplanar image acquisition and segmentation for expanding the SHWS dynamic range to a dynamic range based on avoiding the overlap of lenslet images and sufficient sampling accuracy for measurement. This also resolves the issue of mandating the determination of centroid exclusively within the corresponding detection area. We perform a comparative analysis between our proposed method and a conventional method for measuring large wavefronts, utilizing both numerical simulations and experiments. Additionally, we conducted a statistical analysis of the dynamic range of our method, and the results indicate that the dynamic range using this method has improved 2.7 to 9 times compared to the dynamic range of conventional algorithms