A simple model of holography and some enhanced resolution methods in electron microscopy

A simple pictorial model of electron interference effects based on an exten ded representation of the autocorrelation function is described and develop ed. Unlike Abbe's theory of transmission imaging, the model incorporates fu lly the effect of the loss of phase that occurs in the detector plane. The aperture transfer function and information limit (envelope function) are al so incorporated with reference to the simplest scattering geometry of Young 's slits. The model is then applied to holography, the diffraction phase pr oblem, ptychography, Wigner distribution deconvolution, conventional bright -field imaging, single side-band imaging and tilt-series reconstruction. So me of these methods require an understanding of four-dimensional integral f unctions, but the model reduces the problem into a projection of a two-dime nsional space. It is hoped that the model will help material scientists who are not specialists in imaging and diffraction theory to understand some r ecent developments in advanced super-resolution imaging methods. (C) 2001 E lsevier Science B.V. All rights reserved.