Dresden 2014 – wissenschaftliches Programm
O 71.4: Vortrag
Donnerstag, 3. April 2014, 11:15–11:30, GER 38
Plasmo-Emission: Nonlinear Emission of Electrons from the Plasmonic Field — •Philip Kahl, Andreas Makris, Simon Sindermann, Michael Horn-von Hoegen, and Frank-J. Meyer zu Heringdorf — Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany
Nonlinear Photoemission Electron Microscopy (PEEM) using ultrashort (<20 fs) laser pulses in a normal incidence geometry has been demonstrated to be capable of observing Surface Plasmon Polaritons (SPPs) in space and time. The advantage of the normal incidence geometry over the commonly used grazing incidence geometry is the fringe spacing of the observed Photoemission pattern, which resembles the SPP wavelength. Furthermore, due to the cylindrical symmetry of this incidence geometry, all propagation directions of SPPs on the surface are imaged equally. This opens the possibility to perform Plasmon-Nanooptics measurements, in which SPPs can be observed propagating in different directions and also being reflected, all with sub-wavelength resolution. In the overlap region of two counter-propagating SPPs the formation of a standing wave can be observed. Curved grating couplers can be used to focus two SPPs propagating in opposite directions into a joint focal point. The resulting standing wave pattern has a characteristic time, space and energy signature of SPP-emitted electrons (Nonlinear Plasmo-Emission) and arises without the need of additional light to trigger Photoemission (classical nonlinear Photoemission).