Performance comparison between Shack-Hartmann and astigmatic hybrid wavefront sensors

Simulations on Kolmogorov phase screens are employed to compare the relative performance of an astigmatic hybrid wavefront sensor (AHS) to that of a Shack-Hartmann sensor (SHS). The AHS is shown to improve phase reconstruction accuracy when the subaperture phase contains significant energy in curvature modes and a moderate to high number of photons are collected. Dual use of the AHS and SHS may extend enhanced reconstruction to low signal levels. The AHS is also shown to have a small benefit for tilt-only reconstruction when the beam has sufficient power.