Distortion-free imaging through inhomogeneities by selective spatial-filtering
Distortion-free imaging through a system with aberrations is possible for a certain class of input. The input spatial spectrum must be restricted to spatial frequencies which are equally affected by the aberrations (i.e., which experience identical phase shifts mod2-pi). We demonstrate experimentally that if the aberrations can be localized in the pupil plane, an arbitrary input can be prefiltered to produce a distribution which is imaged without distortion by an aberrant system. Equivalently, the output of the system can be postfiltered to select the information which was imaged without distortion.