Hannover 2003 – wissenschaftliches Programm
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Q: Quantenoptik
Q 23: Superkontinuum in nichtlinearen Fasern
Q 23.8: Vortrag
Dienstag, 25. März 2003, 15:45–16:00, F442
A time domain Fresnel lens with coherent control — •Wendel Wohlleben1, Jerome Degert2, Beatrice Chatel2, Marcus Motzkus1, and Bertrand Girard2 — 1MPI für Quantenoptik, D-85748 Garching — 2IRSAMC, Universite Paul Sabatier, F-31062 Toulouse
Perturbative chirped pulse excitation of a two-level system leads to oscillations in the excited state amplitude. These time-domain oscillations are mathematically identical to the spatial fringes visible on a screen behind a sharp edge that partly blocks a laser beam. Here the temporal position of an ultrashort probe pulse within the long excitation pulse corresponds to the spatial position of a sharp edge in the beam profile. By direct analogy with Fresnel zone lenses we conceive highly phase-amplitude modulated pulse shapes that slice destructive interferences out of the excitation time structure and enhance the final population [1]. The expectations from the numerical solution of the non-linear Schrödinger equation are quantitatively matched by the experimental realization with shaped femtosecond excitation of Rubidium atoms.
[1] J. Degert, W. Wohlleben, B. Chatel, M. Motzkus and B. Girard, Phys. Rev. Lett. 89 (2002) 203003.