Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 38: Nano-optics of metallic and semiconducting nanostructures (experiments I)
O 38.3: Vortrag
Mittwoch, 25. März 2009, 15:30–15:45, SCH A216
Antenna enhanced Pump-Probe Spectroscopy of Single Metal Nanoparticles — •David Molnar1,2 and Markus Lippitz1,2 — 1Max-Planck-Institut für Festkörperforschung, Stuttgart — 24. Physikalisches Institut, Universität Stuttgart
Tailoring a nanoparticle's properties for technological applications requires a profound understanding of its different characteristics compared to those of its bulk material. One arising question is: Down to which lengths can a material be expected to show bulk behaviour?
Acoustical eigenfrequencies of a single gold nanoparticle give insight to its mechanical properties such as density or Young's modulus. A laser induced mechanical oscillation yields a periodical change of the electron density, i.e., a periodically changing plasmon resonance. This change is optically detectable using a pump-probe technique and reveals the dynamics of the particle's oscillation.
As absorption is proportional to the third power of the particle's radius the optical detection of mechanical oscillations of a single metal particle with a diameter of 40nm or less is almost impossible. However using an adequate antenna enhancing the signal oscillations of a single particle, 10nm in size or less, become detectable.
We will show calculations of the signal enhancement by an antenna as well as first experimental results in this field.