Berlin 2008 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 38: Vibrational Spectroscopy of Nanolayers with Optical Probes

DS 38.1: Hauptvortrag

Freitag, 29. Februar 2008, 15:15–15:45, H 2013

Vibrational dynamics on the nanoscale — •Markus Raschke — Department of Chemistry, University of Washington, Seattle, USA

As the spatial dimensions of a medium shrink into the 1 to 100 nm range, concomitant changes in the time scales of the fundamental optical excitations can occur. Here, by combining scattering-type scanning near-field optical microscopy with ultrafast spectroscopy techniques provides simultaneous nanometer spatial and femtosecond temporal resolution. Using transient IR pulses we demonstrate spatio-temporal imaging of block-copolymer nanostructures. The vibrational free-induction decay probed in the optical near-field of the respective molecular subensembles carries information about spatial coherence and intermolecular coupling. In addition, the influence of the tip as an optical antenna on the radiative rates of the induced tip-sample polarization will be discussed.