Hannover 2010 – wissenschaftliches Programm
SYQS 1.4: Hauptvortrag
Donnerstag, 11. März 2010, 12:00–12:30, E 415
Mechanistic laser pulse parameterizations — •Tobias Brixner — Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
Shaped femtosecond laser pulses offer a powerful tool for coherent control. Depending on the type of problem, the optimal parameterization of phase, amplitude, and polarization properties may differ, especially if mechanistic insight is desired in addition to control performance. Here, several types of parameterization for femtosecond laser pulses will be discussed.
In the first case, control of the so-called Wolff rearrangement offers an example for a photochemical bond-breaking and bond-formation reaction in liquid phase, and non-restricted adaptive pulse shaping is compared with linear-chirp and spectral triangular-phase parameterizations. In the second example, the von Neumann time-frequency distribution is introduced and applications in molecular control are suggested. Experimental quantum control landscapes are recorded, and the performance in adaptive optimizations is compared with the pulse-shaper pixel basis. In the third example, the parameterization is chosen such that the control mechanisms in ultrafast nano-optics are mirrored exactly. Thus a generally valid analytic solution for the control problem is found, and the global optimum is obtained in a direct, non-iterative fashion. First experiments using the analytic solution confirm these predictions.