Processing of off-axis electron holography data of an electrically biased Fe needle using the holography package in Hyperspy. a) Original electron hologram. The inset shows an enlargement of the area outlined by a red square. b) Fourier transform of the hologram, with a sideband used for reconstruction outlined with a red square. c) Unwrapped phase of the reconstructed wave, containing contributions from the mean inner potential of the and both the magnetic field and the electric field of the needle. d) Wrapped phase image showing only the contribution of the electric field. The needle shape is outlined by a dashed black line. The data and experiment are described in Migunov et al. J. Appl. Phys. 117, 134301 (2015).
A Python-based software package is available for the basic reconstruction and analysis of off-axis electron holograms for electromagnetic field mapping. This code is part of an open-source software package for the multidimensional data analysis toolbox HyperSpy, which is distributed under the GPL-3.0 license.
The holography capability in HyperSpy allows parallel reconstruction and processing of multidimensional hologram stacks, denoising of holograms using different algorithms based on (principal) component analysis and flexible input and output of multidimensional data.