HIGH-RESOLUTION SPHERICAL-ABERRATION-FREE PHASE IMAGING BY DEFOCUS IMAGE MODULATION PROCESSING UNDER HOLLOW-CONE ILLUMINATION - EXPERIMENTAL CONFIRMATION BY OPTICAL MICROSCOPY

Hollow-cone imaging as applied to DIMP enables the resolution of the e lectron microscope to be significantly improved under spherical-aberra tion-free observation, as has recently been proposed. To confirm this, optical microscopic approach has been used. The experiment has clearl y confirmed that the spherical-aberration-free complex wavefield at th e exit surface of the specimen has been retrieved with the resolution 1.8 limes higher than under axial illumination, leading to the realiza tion of a new type high resolution electron microscopic observation, D IMP-EM under hollow-cone illumination.