Holographic Imaging of Bose-Einstein Condensates
Summary
Bose-Einstein condensates are interesting systems for studying quantum mechanics. Absorption imaging and phase-contrast imaging are two methods that are often used to determine the absolute number of atoms in a condensate. This thesis proposes a third method: holographic imaging. This method relies on the interference of a probe beam, which passes through the condensate, and a reference beam. The phase shift of the light due to the atoms and the optical density of the condensate are reconstructed with the use of Fourier transformation. Up to 300 images can be taken \textit{in situ}.
There are two interesting applications of holographic imaging. The first is the refractive index, which can be measured directly with holographic imaging. The Hartree-Fock model is used to relate the real and imaginary part of the refractive index to the degeneracy of the condensate. However, the preliminary results are ambiguous and require further study.
The second is spin-dependent imaging, in which two orthogonally polarized reference beams are used to reconstruct polarization dependent information. This can be applied to study the dynamics of spinor condensates. In this thesis, a proof of concept for this method is given.