title: Exploiting lens aberrations to create electron-vortex beams.
abstract: A model for a new electron-vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. The vortex beam is produced through a particular alignment of these lenses into a specifically designed astigmatic state and applying an annular aperture in the condenser plane. Experimental results are found to be in good agreement with simulations.
authors: EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium. laura.clark@ua.ac.be
authors: L
authors: L
authors: Clark
authors: A
authors: A
authors: Béché
authors: G
authors: G
authors: Guzzinati
authors: A
authors: A
authors: Lubk
authors: M
authors: M
authors: Mazilu
authors: R
authors: R
authors: Van Boxem
authors: J
authors: J
authors: Verbeeck