Evaluating response calculation methods for thin and volume analog holographic wavefront sensors

The modal analog holographic wavefront sensor (AHWFS) is a low-cost and high-speed solution for wavefront sensing. It uses a phase biasing approach, where a pair of holograms are biased with a known phase delay/advance. The aberration magnitude is determined by measuring the diffracted beam intensities from the hologram pair. Both thin and volume phase transmission holograms can be used. Thin gratings produce multiple diffracted orders, while volume gratings direct light into a single order. Sensor response is measured using photodiodes or cameras, though thin holograms require a small region of interest for sensitivity to changing aberration magnitudes. This work compares response calculation methods, based on both an integrated intensity and, a weighted average and thresholding method, for thin and volume holograms recorded in self-developing photopolymer film. In particular, we focus on analysing the performance of both methods under emulated atmospheric turbulence conditions.