A spatial phase-shifting method for real-space wave reconstruction of off-axis electron holograms

Abstract

Abstract The Fourier transform with a side-band filter is the well-established method for reconstructing off-axis fringe-type holograms due to its ease of implementation and fast processing. However, this method works in reciprocal space and requires inversion of a side-band sub-region, which can degrade the spatial resolution of reconstructed wave compared to the original hologram. We present a new method, the spatial phase-shifting (SPS) method, for real-space wave reconstruction of off-axis electron holograms. We describe the working principles of the SPS method in analogy to the temporal phase-shifting method. We conducted both hologram simulations and experiments to evaluate its applicability and effectiveness. We compared the wave reconstruction results of the SPS and the conventional Fourier transform method, highlighting the advantages of the newly proposed SPS method. Our results demonstrate that the proposed SPS method is particularly effective for real-space wave reconstruction of small-sized hologram, providing an alternative approach to off-axis type holography wave reconstruction.