Dither-based sensor for improved consistency of adaptive optics system

Abstract

The wavefront reconstruction accuracy in Shack Hartmann sensor based adaptive optics system depends on accurate centroiding and phase estimation from measured slope values. Monte Carlo simulations of vector matrix multiply and Fourier phase estimation methods show fluctuations in the value of wavefront reconstruction accuracy leading to inconsistency. In this paper, it is shown that these fluctuations can be minimized and high wavefront reconstruction accuracy can be maintained consistently by applying a dither signal on the Shack Hartmann lenslet array. The information of the dither signal to be applied can be obtained from the wavefronts of the past.