Abstracts

Seedat, Adam — Optimized beam shapes for atom interferometry

The sensitivity of atom interferometers to detect small changes in gravity is very important. Among other factors, the sensitivity of these devices is limited by the interference fringe contrast. Contrast is itself limited by dephasing, the decoherence of the Rabi oscillations of atoms over time. One method of reducing contrast which hasn’t been explored much in the literature is by using a more optimum intensity profile of the interferometry beams incident on the atoms. Hence, I will present a method of determining the optimum profile of an atom interferometer for dephasing reduction. This is based around finding the appropriate trade-off between beam profile uniformity (which reduces dephasing caused by the intensity distribution of the beam) and the beam profile amplitude (which reduces dephasing caused by the velocity spread of the atoms). Whilst I will demonstrate the application of this method to increase the contrast of one of the atom interferometers in a gravity gradiometer, this method can be used to increase the contrast of any atom interferometer without requiring additional beam power or lower atom temperatures.