Tomography of particle plasmon fields using EELS
Anton Hörl
13:00 - 14:00 Friday 26 June 2015 HS 05.12 Physikgebaeude, Universitätsplatz 5

Electron energy loss spectroscopy (EELS) and microscopy allow probing of the evanescent fields of particle plasmons with nanometer resolution. In EELS, electrons with a high kinetic energy pass by or penetrate through a metallic nanoparticle, excite particle plasmons, and lose part of their kinetic energy. By monitoring the energy loss as a function of electron beam position, one obtains detailed maps about the localized plasmonic fields .

In this talk, I show how to extract the three-dimensional plasmon fields from a sinogram of EELS maps. We develop a general tomography scheme that can be generalized for larger nanoparticles without employing the quasistatic approximation. Our approach is based on a decomposition of the Green’s tensor into modes which are reconstructed by means of compressed sensing. We demonstrate the applicability of our approach for different plasmonic structures, showing that the reconstructed data provide most detailed information about the 3d plasmonic field distribution.