Abstract

Zonal wavefront sensing can be made more accurate with one fully characterized quadratic surface in each subaperture, if all the first and second order terms of local wavefront can be detected [1].The only proposal that has accomplished this feat with a single focal image (FI) is the astigmatic hybrid sensor (AHS) in [2] with added artificial neural network (ANN) postprocessing [3]. Since the AHS can only provide a simple intensity-normalized signal linear with the defocus of local wavefront [2], the ANN postprocessing has to be introduced to resolve the complicated nonlinear mapping between the second order terms of local wavefront and the pixelized intensity distribution of FI [3].

© 2017 IEEE