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π/2 mode converters and vortex generators for electrons.

C Kramberger1, S Löffler2, T Schachinger3

  • 1Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10/E138, Wien 1040, Austria.

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|May 25, 2019
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Summary
This summary is machine-generated.

Researchers explored asymmetric quadrupole lenses for electron optics to create electron vortex beams. This advancement could lead to new vortex generators for high-brilliance electron probes at the atomic scale.

Keywords:
Electron microscopyMode conversionOrbital angular momentumVortex beams

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Area of Science:

  • Electron optics
  • Beam manipulation
  • Vortex beam generation

Background:

  • Mode conversion in optics, such as switching between Hermite Gaussian and Laguerre Gaussian beams, imparts orbital angular momentum and creates vortices.
  • In electron optics, quadrupole lenses are analogous tools for achieving similar beam transformations.

Purpose of the Study:

  • To investigate generalized asymmetric designs for quadrupole mode converters.
  • To assess the feasibility of these designs within existing electron microscope constraints.
  • To guide the development of dedicated vortex generators for electron vortex probes.

Main Methods:

  • Theoretical investigation of generalized asymmetric quadrupole lens designs.
  • Analysis of mode conversion capabilities for Hermite Gaussian to Laguerre Gaussian beams.

Main Results:

  • Demonstrated that asymmetric quadrupole designs can be realized within current electron microscope technology.
  • Identified potential for creating electron vortex beams with specific properties.

Conclusions:

  • Asymmetric quadrupole mode converters offer a viable path for generating electron vortex beams.
  • This research paves the way for advanced electron vortex probes with atomic-scale resolution.