An Integrated Optical-Waveguide Chip for Measurement of Cold-Atom Clouds

This thesis introduces the first demonstration of a monolithic, micro-fabricated, multi-channel, optical-waveguide chip to measure ultra-cold atomic clouds. The optics consist of an array of 12 independent junctions, which are separated by only 10 μm and have large atom-photon coupling. The integrated and scalable design is presented, along with an atom chip for mounting the optical waveguide chip and magnetically trapping and handling ultra-cold atoms. The experimental apparatus which was built to accommodate this new chip set is described, along with a new experimental control programme which was developed to accommodate the scalability requirements of the new chip. The chip was optically, mechanically and magnetically characterised and cold atoms with densities up to 10-² μm-³, corresponding to 1 atom at a time inside the waveguide mode, were detected with this new kind of chip using absorption and fluorescence techniques. Subsequently, the atoms were utilised to diagnose light polarisation and intensity within the optical-waveguide chip. For future use, various detection methods adapted to the optical-waveguide chip were considered to minimise photon scattering and thus heating of a trapped ultra-cold sample of atoms