title: Three-wave electron vortex lattices for measuring nanofields.
abstract: It is demonstrated how an electron-optical arrangement consisting of two electron biprisms can be used to generate three-wave vortex lattices with effective lattice spacings between 0.1 and 1 nm. The presence of vortices in these lattices was verified by using a third biprism to perform direct phase measurements via off-axis electron holography. The use of three-wave lattices for nanoscale electromagnetic field measurements via vortex interferometry is discussed, including the accuracy of vortex position measurements and the interpretation of three-wave vortex lattices in the presence of partial spatial coherence.
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany. Electronic address: c.dwyer@fz-juelich.de.
authors.forename: C
authors.initials: C
authors.lastname: Dwyer
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: C B
authors.initials: CB
authors.lastname: Boothroyd
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: S L Y
authors.initials: SLY
authors.lastname: Chang
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: R E
authors.initials: RE
authors.lastname: Dunin-Borkowski
keywords: Holography; Partial coherence; Vortex; Vortex lattice