Three-wave electron vortex lattices for measuring nanofields

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. - Highlights: • We demonstrate how three-wave electron vortex lattices can be generated using two electron biprisms in the TEM. • The optical setup can be used to measure nanoscale electromagnetic fields via vortex interferometry. • The presence of vortices is verified explicitly by using a third biprism to perform phase measurements. • The accuracy of vortex position measurements and the requirements of spatial coherence are discussed