Reconstruction of in-line holograms by lateral tomography

Calculated electron in-line holograms, for the low-energy electron point source (LEEPS) microscope and based on scattering theory, give reconstructions that exhibit atomic resolution perpendicular to the optical axis. The depth resolution is not as sharp, and spurious peaks also result. We investigate the depth resolution in the reconstruction of LEEPS in-line holograms using a tomographic approach, by sampling several abject positions with displacements lateral to the optical axis. We inquire as to whether or not (i) lateral tomographic holograms and their reconstructions, (ii) averaging over a discrete number of lateral displacements, reveal any significant improvements. We also investigate whether or not laterally shifting the screen improves the depth resolution. The experimental consequences of these inquiries are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.