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Promotionsvortrag Physik: "Hocheffiziente Licht-Materie Wechselwirkung"

Dec 01
December 1, 2020 9:00 am - 10:30 am
Online Video-Konferenz unter Ausschluss der Öffentlichkeit

Ankündigung des Promotionsvortrags von: Herrn Martin Fischer

The most fundamental aspect of light-matter interaction is light controlling a single emitter such as a single atom. In many experiments this is done by using comparatively high light levels in order to reach the desired effect on the atom. This approach, while suitable for tasks such as quantum computing or high precision optical clocks, neglects the second part of light-matter interaction, i.e. the effect that the emitter can have on the light field.

In order to optimize the interaction between light and matter, and therefore the effect that the two can have on each other, it is necessary to mode match the light field to the emission pattern of the atom. In free space – and for the ubiquitous electric dipole transition – this requires the generation of an incoming dipole mode that is focused onto the target.

In this talk experiments utilizing a single trapped ion in the focus of a deep parabolic mirror will be described. The mirror is used to transform a suitable plane wave into the required linear dipole mode. The coupling efficiency of the setup will be verified by measuring the effect of the light field onto the atom at different power levels. Additionally, the trapped ion was used to probe the intensity of the electric field at different positions to measure the point spread function of the imaging system compatible with a resolution of better than half a wavelength. Furthermore, the atom was used to shift the phase of a weak coherent beam, leading to phase shifts of up to 2.2 degrees and witnessing the back action of the matter target onto the light field by which it is excited.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind aufgrund der momentanen Situation nicht öffentlich. Diesen Verfahrensteilen folgt ein ebenfalls nicht öffentliches Rigorosum von 45 Minuten.