ISBN 9783843917988

978-3-8439-1798-8, Reihe Physik

André Wenzlawski
Matter-wave optics in microgravity: Laser technology and applications

145 Seiten, Dissertation Universität Hamburg (2013), Softcover, A5

Zusammenfassung / Abstract

Atom interferometry emerged as a key technology in the last decades, especially for applications requiring extremely precise measurements.

These applications include the measurements of inertial forces like gravity or rotations, e.g. for geodesy or navigation, but also questions on fundamental physics, like a test of the weak equivalence principle, can be addressed with these devices.

An approach for increasing the sensitivity of atom interferometers is their utilization in weightlessness.

As the sensitivity of an atom interferometric measurement scales with the square of the available observation time, the gravitational acceleration on earth is generally one of the main limiting factors. In weightlessness, the atoms and the apparatus are falling in the same rest frame, so no relative accelerations are existing.

One of the main experimental challenges of these types of experiments is the extremely long free fall time after which the interferometer has to be read out. After a time of free expansion an atomic ensemble has a size depending on its temperature, and as several perturbations come with the size, a maximal cold atomic ensemble is the desired starting point for atom interferometers in microgravity.

In this thesis, the first demonstration of a Bragg interferometer based on a Bose-Einstein Condensate (BEC) in microgravity, namely in the drop tower in Bremen will be presented. Additionally the application of a further cooling technique to reduce the velocity spread of the BEC, the delta-kick cooling, is shown.