Shack–Hartmann wavefront sensor with enhanced dynamic range and reference-free operation

Large dynamic range Shack–Hartmann wavefront sensor based on holographic multipoint generation and pattern correlation

“…This connection between accuracy and dynamic range has led to the development of numerous SHS variations. [11][12][13][14][15][16] Kumar et al used hexagonal indexing to assign the spots to their original subapertures. 11 Another approach is to use the assumption of steady curvature of the wavefront to apply a tracking algorithm.…”

“…[11][12][13][14][15][16] Kumar et al used hexagonal indexing to assign the spots to their original subapertures. 11 Another approach is to use the assumption of steady curvature of the wavefront to apply a tracking algorithm. 12,17 In references 10,[13][14][15][16] the microlens array is replaced by a liquid crystal display or a shiftable aperture to create an adaptive SHS.…”

“…In the context of this article, measurement accuracy is meant to be the statistical measurement uncertainty for a calibrated sensor. This connection between accuracy and dynamic range has led to the development of numerous SHS variations 11 – 16 Kumar et al.…”

“… – 16 Kumar et al. used hexagonal indexing to assign the spots to their original subapertures 11 . Another approach is to use the assumption of steady curvature of the wavefront to apply a tracking algorithm 12 , 17 .…”

Large dynamic range Shack-Hartmann wavefront sensor based on adaptive spot matching

“…Nevertheless, these hardware modifications increase the system complexity and measurement duration, in contrast to algorithm-based methods that do not require changes to the current setup. Instead, spot-matching algorithms, including unwrapped algorithms 23 , iterative extrapolation [24][25][26][27][28] , neighborhood search 29 , and spot sorting 30,31 were utilized. These algorithms can directly match spots that extend beyond the boundaries of the individual microlenses, thereby enabling the determination of larger displacements.…”