ISBN 978-3-8439-1939-5

978-3-8439-1939-5, Reihe Physik

Andreas Kölle
Coherent Phenomena in Four-Wave Mixing via a Rydberg State in Thermal Vapor of Rubidium

128 Seiten, Dissertation Universität Stuttgart (2014), Hardcover, A5

Zusammenfassung / Abstract

In this thesis the coherent emission of light, based on the effect of four-wave mixing in a thermal ensemble of rubidium atoms, will be presented. This effect is gained by the resonant coupling of three laser light fields to atomic transitions, which fulfill the condition of energy and momentum conservation. The thermal motion of the atoms and the resulting Doppler-shift in combination with this momentum conservation, or in other words the phase matching condition, lead to the unintuitive effects of interference.

These effects will be studied in detail by comparing a theoretical model with measurements, utilizing a 5D-state or a Rydberg state, conducted with CW laser light. Followed by studies of the temporal evolution of the coherent effects utilizing a pulsed excitazion to the Rydberg state. The last experimental chapter discusses the feasibility of reducing the excitation volume to a length scale on the order of 1 micrometer by means of a tightly focused laser beam. For the modeling of this nontrivial geometrical configuration a target mode formalism is introduced.