Femtosecond Microscopy of Surface Plasmon Polariton Wave Packet Evolution at the Silver/Vacuum Interface

Abstract
A movie of the dispersive and dissipative propagation of surface plasmon polariton (SPP) wave packets at a silver/vacuum interface is recorded by the interferometric time-resolved photoemission electron microscopy with 60 nm spatial resolution and 330 as frame interval. The evolution of SPP wave packets is imaged through a two-path interference created by a pair of 10 fs phase correlated pump−probe light pulses at 400 nm. The wave packet evolution is simulated using the complex dielectric function of silver.