Phase retrieval of an electron vortex beam using diffraction holography
Abstract
In both light optics and electron optics, the amplitude of a wave scattered by an object is an observable that is usually recorded in the form of an intensity distribution in a real space image or a diffraction image. In contrast, retrieval of the phase of a scattered wave is a well-known challenge, which is usually approached by interferometric or numerical methods. In electron microscopy, as a result of constraints in the lens setup, it is particularly difficult to retrieve the phase of a diffraction image. Here, we use a defocused beam generated by a nanofabricated hologram to form a reference wave that can be interfered with a diffracted beam. This setup provides an extended interference region with the sample wavefunction in the Fraunhofer plane. As a case study, we retrieve the phase of an electron vortex beam. Beyond this specific example, the approach can be used to retrieve the wavefronts of diffracted beams from a wide range of samples.
Cite
@article{arxiv.1703.08496,
title = {Phase retrieval of an electron vortex beam using diffraction holography},
author = {Federico Venturi and Marco Campanini and Gian Carlo Gazzadi and Roberto Balboni and Stefano Frabboni and Robert W. Boyd and Rafal E. Dunin-Borkowski and Ebrahim Karimi and Vincenzo Grillo},
journal= {arXiv preprint arXiv:1703.08496},
year = {2017}
}