Heidelberg 2015 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 21: Posters 4: Novelties in Molecular Physics

MO 21.7: Poster

Donnerstag, 26. März 2015, 17:00–19:00, C/Foyer

Realization of ultrafast time resolved spectroscopy using a Kretschmann arrangement — •Alireza Mazaheri Tehrani, Faezeh Mohaghegh, and Arnulf Materny — Jacobs University, Campus Ring 1, 28759 Bremen, Germany

The interactions of molecules adsorbed on thin metal films with surface plasmon polaritons are of great importance for spectroscopic applications, such as surface enhanced Raman spectroscopy (SERS). So far, experimental SERS investigations have mostly been performed in the frequency domain using continues wave lasers. This way, although the results are quite interesting concerning applications, they mostly fail to nicely address the underlying physical concepts and mechanism of SERS. Time-resolved experiments, however, would help us to gain a better understanding of the underlaying energy transfer mechanisms between electronic systems of metal and adsorbate due to their different time scale characteristics. In order to study the interaction in a reproducible manner, we use a Kretschmann configuration setup, through which surface plasmons were excited with femtosecond laser pulses (Pump) adjusted to the ground state absorption. Dynamic information of the system, could then be probed by another time-delayed femtosecond laser pulse, which could freely be adjusted to other excited states of adsorbates or to the ground state absorption. This experiment provides us with a much deeper insight into the energy transfer mechanisms between SPPs and molecules. In our contribution, we will present and discuss the time-resolved results.