Popularized in the 1990's, electron energy loss spectroscopy (EELS) consists in using a beam of fast-moving electrons which energy is known, to scan a device and/or a material. The non-zero probability of each electron to interact with the structure produces a measurable energy loss, thus providing information on the structure. In particular, various plasmonic resonances can be investigated when the electron beam passes close to the sample.
Here, we show a time-lapse of a surface plasmon being excited on a 10nm-radius aluminium sphere by a sweeping electron beam. The impact parameter (minimal distance between the electron trajectory and the sphere surface) is 1nm.
Simulation of electromagnetic waves propagation in nano-optics with a high-order discontinuous Galerkin time-domain method