Ultrafast Nanooptics

                   PD Dr. Walter Pfeiffer
       Physikalisches Institut der Universitaet Wuerzburg


 Collective electron dynamics at interfaces are of fundamental importance
 for many different aspects in surface science, like surface chemistry,
 catalysis and electronic properties of nanostructured surfaces. The
 presentation covers time-resolved experiments using supported Ag
 nanoparticles illustrating the role of collective excitations in
 two-photon-photoemission. In a second part more general aspects of the
 excitation of plasmons with ultrashort polarization shaped laser pulses
 is discussed. The optical near field in the vicinitiy of arbitrarily
 shaped nanoscale objects is utilized to control the spatial and temporal
 evolution of the electric field. This control mechanism opens new routes
 to time-resolved spectroscopy on the nanoscale.