Experimental realization of a π/2 vortex mode converter for electrons using a spherical aberration corrector

• DOI: 10.1016/j.ultramic.2021.113340
• Publication Date: 2021-06-27T08:58:23Z
• Authors: T. Schachinger; P. Hartel; P.-H. Lu; S. Löffler; M. Obermair; M. Dries; D. Gerthsen; R.E. Dunin-Borkowski; P. Schattschneider
• Keywords: Optical vortex

In light optics, beams with orbital angular momentum (OAM) can be produced by employing a properly-tuned two-cylinder-lens arrangement, also called $\pi$/2 mode converter. It is not possible to convey this concept directly the beam in an electron microscope due non-existence of cylinder lenses commercial transmission (TEM). A viable work-around are readily-available optical elements form quadrupole lenses. proof-of-principle experiment 2012, it has been shown that single combination Hilbert phase plate produces spatially-confined, transient vortex mode. Here, analogue converter realized repurposing CEOS DCOR probe corrector aberration corrected TEM way resembles dual lens using two quadrupoles. order verify presence OAM output beam, fork dislocation grating used as analyser. The possibility use magnetic fields instead of, e.g., prefabricated gratings produce carrying enhances brightness almost magnitude and delivers switchable high-mode purity without unwanted side-bands.