Hannover 2010 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 21: Poster I
Q 21.32: Poster
Dienstag, 9. März 2010, 16:00–19:00, Lichthof
Matter wave interferometry for determination of molecular transition dipole moments — •Sha Liu, Horst Knöckel, and Eberhard Tiemann — Institut für Quantenoptik, Leibniz Universität Hannover
A molecular matter wave interferometer has been employed to measure the molecular transition dipole moment of the B1Πu - X1Σg+ transition of K2. A K2 beam is created in a supersonic expansion of potassium vapor out of a nozzle. A pair of laser beams works as beam splitters to coherently split the matter wave, employing the b3Π0u+ - X1Σg+ transition. The high collimation of the molecular beam yields a large coherence length in transverse direction, such that under the given experimental conditions the two outgoing matter waves overlap laterally, establishing a Ramsey type matter wave interferometer. The phase difference between the matter waves is sensitive to phase drifts of the optical phases of the beam splitters, therefore the optical phases of the beam splitters are locked with respect to each other for high long term stability. A near resonant laser field is introduced between the laser beams for the beam splitter. This field couples near resonantly the ground state level of the beam splitter transition with an excited level of the B1Πu state. Thus the passing molecule feels a potential hill or valley depending on the detuning. The phase shift of the matter wave interference by the AC-Stark effect is used to determine the transition dipole moment of the B-X transition of K2. Details of the experiment and results and experience regarding the prospect of a matter wave interferometer in such applications will be presented.