Ralf Vogelgesang

At the 5th Workshop on Numerical Methods for Optical Nano Structures, ETH Zürich, July 2009.

In recent years surface plasmon polaritons (SPPs)—either propagating or localized at metal−dielectric interfaces—have attracted renewed interest. On the one hand, advances in nanotechnology made the fabrication of resonant plasmonic structures feasible even for visible wavelengths. On the other hand, a growing variety of near-field optical characterization techniques are coming of age. Resonant plasmonic structures for applications at terahertz to visible wavelengths can now be studied by means well beyond conventional far-field scattering micro-spectroscopy of particle ensembles. Single particles are now routinely performed and several techniques have become available to go beyond the spatial diffraction limit of resolution in imaging of nano-plasmonic effects. We will review developments of the last few years in techniques like two-photon luminescence (TPL), electron energy loss spectroscopy (EELS), photoemission electron microscopy (PEEM), and scanning near-field optical microscopy (SNOM), highlighting selected results and open questions from both experimental studies as well as theoretical modeling.