Absorption Spectroscopy of a K+Cs Mixture Cell and Simulation of Time-Averaged Optical Potentials

Abstract

In the first part of the report, Doppler-broadened absorption spectroscopy was performed on a natural abundance K+Cs mixture species cell to determine whether interspecies molecular transitions are observable at sufficiently high vapour pressures. It was found that the cell behaves independently of the presence of the other alkali metal for spectroscopy on both the Cs D2 and K D2 lines for a temperature range between 27.8 - 45.4 degrees Celsius, and 34.8 - 150 degrees Celsius, respectively. Above the temperature of 155 degrees Celsius, the spectroscopic signal on the K D2 line exhibits absorption features which is potentially the result of rotational transitions in the K2 molecule, however, this is not definitive and further investigations are needed to confirm this.

In the second part, we developed and tested several codes on a MATLAB program to simulate time-averaged potentials using an acousto-optic modulator (AOM). We demonstrated three different coding methods to generate smooth trapping potentials and characterised different parameters required to accomplish such a potential. We also investigated the depth of the trapping potential of a harmonic potential and the requirements to accurately approximate the trap frequencies.