Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 59: Plasmonics and Nanooptics
O 59.13: Poster
Dienstag, 21. März 2017, 18:30–20:30, P2-OG1
Signatures of strong coupling on nanoparticles: Revealing absorption anticrossing by tuning the dielectric environment — •Felix Stete1,2, Wouter Koopman1, and Matias Bargheer1,3 — 1Institut für Physik & Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany — 2Humboldt-Universität zu Berlin, School of Analytical Sciences Adlershof (SALSA), Unter den Linden 6, 10999 Berlin, Germany — 3Helmholtz Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin, Germany
This contribution presents a method to unambiguously identify the strong coupling regime in plasmon-exciton core-shell systems via absortpion measurements. Two examples of core-shell nanoparticles were used, both with a shell of the J-aggregate forming cyanine dye TDBC and a gold core. In one case the core was formed by gold nanospheres, in the other by gold nanorods. The resonances were tuned by changing the particles' environment on a substrate by layer-by-layer deposition of thin polyelectrolyte films replacing air und thus shifting the plasmon resonance. The extinction spectra of both systems show an anticrossing indicating a regime of strong coupling. However true absorption spectra reveal that only the rods are strongly coupled whereas the spheres' absorption does not show an anticrossing indicating that the spheres are rather in a regime of induced transparency. The observations are discussed within a classical coupled oscillator model that reveals differences in contributions from excitons and plasmons.