Stuttgart 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MO: Fachverband Molekülphysik
MO 1: Vibrational Spectroscopy
MO 1.5: Vortrag
Montag, 12. März 2012, 11:45–12:00, V38.03
Coherent Anti-Stokes Raman Scattering (CARS) with tunable broadband excitation and narrowband probe pulse — •Matthias Lütgens, Susana Chatzipapadopoulos, and Stefan Lochbrunner — Universität Rostock, Institut für Physik, 18055 Rostock
Coherent anti-Stokes Raman scattering (CARS) spectroscopy is a powerful tool to investigate vibrational modes and their pure dephasing parameters. We present a CARS technique which involves a broadband, coherent excitation of one or several vibrational modes covering a broad range of vibrational frequencies via a femtosecond, broadband Stokes and a narrowband Raman pump beam. The coherent superposition is probed with a narrowband probe beam in the ps range. For this purpose we developed a narrowband ps - non-collinear optical parametric amplifier (NOPA) that allows us to measure CARS time traces with significant higher spectral resolution compared to other fs- CARS setups without losing the ability to monitor dephasing times by the use of time-delayed probe pulses. The capability of the here presented setup is demonstrated by applying this method to different model systems. We show characteristic CARS spectra including numerical simulations of the signal that allows the determination of the energetic position of vibrational modes as well as the dephasing time T2.