Enhanced dynamic range of the Grating array based zonal wavefront sensor using a zone wise scanning method

Grating array based zonal wavefront sensor (GAZWFS), using an array of gratings implemented with a liquid crystal spatial light modulator (LCSLM) to display the gratings, offers a flexible measurement approach. But the wavefront with a large slope may not accurately be sensed by the sensor like any Shack-Hartmann type sensor. In this paper, we propose a zone wise scanning method to improve the dynamic range of GAZWFS by blocking and unblocking the individual gratings. The estimation of the wavefront and expansion of the dynamic range of GAZWFS by the zone wise scanning method is demonstrated by numerical simulation and a proof-of-principle experimental implementation.