By illuminating an Archimedean spiral structure in an Ag film for coupling of surface plasmon polaritons, with linearly polarized light, we create a plasmonic vortex with a defined geometrical charge. The spin-orbit interaction of light generates the topological spin texture. We image the time and space evolution of the plasmonic fields, with 0.1 fs (10-16 s) and <20 nm (2x10-8 m) resolutions by detecting photoelectrons emitted by a two-photon photoemission process that are imaged by a photoemission electron microscope. The raw data has an unmodulated component, so we perform Fourier filtering.
Plasmonic vortex
Raw data
Fourier filtered data