Hamburg 2009 – scientific programme

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MO: Fachverband Molekülphysik

MO 6: Quantenkontrolle 2

MO 6.1: Talk

Monday, March 2, 2009, 16:30–16:45, VMP 6 HS-G

The von Neumann representation as a basis for coherent control experiments — •Christoph Stolzenberger¹, Stefan Ruetzel¹, Susanne Fechner¹, Frank Dimler¹, David J. Tannor², and Tobias Brixner¹ — ¹Institut für Physikalische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany — ²Department of Chemical Physics, Weizmann Institute of Science, 76190 Rehovot, Israel

Laser pulse representations in phase space, i.e. in a joint-time-frequency representation, are a convenient way to simultaneously show both temporal and spectral features. A novel representation, which is based on an idea of von Neumann, for describing more intuitively shaped ultrashort laser pulses, was recently introduced by our group.

Here we demonstrate applications in pulse shape optimizations using evolutionary algorithms and in generating intuitive fitness landscapes. For this purpose we carried out a demonstration experiment using the cooperative second-harmonic signal of two time delayed copies of the shaped pulse as feedback.

Moreover we used this basis for the study of the excitation efficiency of the laser dye molecule IR-140 in solution. Results of chirp dependent fluorescence measurements are compared to those obtained by excitation with pulses defined in the von Neumann plane.