Berlin 2014 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 6: Femtosecond Spectroscopy 1

MO 6.5: Vortrag

Dienstag, 18. März 2014, 11:45–12:00, BEBEL HS213

IR-Vis Two-Photon Fluorescence Spectroscopy on Oxacine1 — •Frank Friedriszik and Stefan Lochbrunner — Universität Rostock, Institut für Physik, Universitätsplatz 3, 18055 Rostock

We present an infrared-excitation Raman-probe setup in the femtosecond-regime and demonstrate its potential by two photon absorption and time-resolved fluorescence measurements on a dye. A regenerative Ti:sapphire amplifier system generating ultrashort laser pulses at 800 nm serves as primary light source. One part of its output is spectrally narrowed by laser line filters and will be used as Raman-probe. Another part of the pump light in converted to infrared radiation by an optical parametric amplifier and a non-collinear difference frequency mixing stage. The time resolution of the setup is better than 700 fs as it was measured by sum frequency mixing of the IR and Raman-probe pulses.

In a first test experiment the fluorescence of the dye Oxacine1 is excited by two-photon absorption of the IR and probe light. The observed fluorescence dynamics with respect to the time delay between the IR and the probe pulse is discussed in the framework of vibrational redistribution processes.