Marcus Rommel^1,2, Stephanie Essig^1,3, Ralf Vogelgesang¹, and Markus Lippitz^1,3

Poster at the Meeting of the DPG in Regensburg, 2010

¹Planck Institute for Solid State Research, Stuttgart, Germany

²Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany

³4th Physics Institute, University of Stuttgart, Stuttgart, Germany

We develop a pump-probe apertureless scanning near-field optical microscope (PPaSNOM) to analyze plasmonic structures. This setup allows us to detect the temporal and spatial dependence of localized surface plasmon resonances (LSPR) as well as propagating SPRs. One of the first applications of this instrument will be the investigation of acoustic vibrations in single plasmonic particles of different shape.

As LSPR's depend sensitively on the electron density, the changes in volume due to GHz acoustic oscillations can be tracked with time-resolving pump-probe experiments [1]. The optical near-field indirectly contains information on the structure's acoustic oscillation. This allow us to extract nanoscale Chladni figures, i.e., maps of the acoustic vibration amplitude on the particle surface.

[1] M. A. van Dijk, M. Lippitz, M. Orrit, Detection of acoustic oscillations of single gold nanospheres by timeresolved interferometry, Phys. Rev. Lett. 2005, 95, 267 406.