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MO: Molekülphysik
MO 51: Molecular Quantum Control
MO 51.6: Talk
Thursday, March 16, 2006, 11:55–12:10, H12
Enhancement of Raman Modes in the Ground State of all-trans-β-Carotene by Coherent Control — •J. Hauer1,2, H. Skenderovic2,3, K.-L. Kompa2, and M. Motzkus1,2 — 1Philipps-Universität, 35032 Marburg — 2Max-Planck-Institut für Quantenoptik, 85748 Garching — 3Institute of Physics, 10000 Zagreb
The vibrational ground state modes of β-carotene in solution are investigated with DFWM (degenerate four wave mixing) under resonant and non-resonant conditions in an open loop coherent coherent control experiment with a spatial light modulator. Two of the three excitation pulses in the sequence are phase modulated by a sine function in order to obtain pulse trains with a well defined spacing between the sub pulses. Comparing the transients after resonant and the non-resonant excitation reveals that modes are not only filtered out but under resonant conditions also enhanced in their intensity compared to the Fourier-limited case. As we demonstrated in an earlier work, no such effect is observed with a non-resonant DFWM-sequence. For a better understanding of this amplification, we conduct a conventional Pump/Probe experiment in an oxazine dye (LD 690). This allows us to demonstrate that the observed effects are due to an enhanced population transfer between electronic states and an increased vibrational coherence.