Improvements in the reconstruction of in-line holograms by energy sampling and tomography

To improve the depth resolution in the reconstruction of in-line holograms taken with the low energy electron point source (LEEPS) microscope we employ, on the basis of a Kirchhoff–Helmholtz-type reconstruction integral, (i) a weighted energy sampling averaging several holograms taken in the energy range 80–200 eV, and (ii) a tomographic approach sampling several screen positions. We calculate electron in-line holograms based on scattering theory and show that their reconstructions exhibit atomic resolution both laterally and in depth without any spurious peaks. The experimental implementation of these schemes is discussed.