Adam W. Anderson

When placed in a cavity, an atom experiences forces due to its interaction with the cavity’s electromagnetic field. We have studied the effect of these forces on the trajectory of an atomic beam both when the cavity contains a laser field and when only vacuum fluctuations are present. This work describes the construction of a micron-sized cavity, through which a beam of cesium or sodium atoms passes. Three experiments are then discussed. (i) It was found that at grazing incidence a large fraction of a cesium beam undergoes specular reflection on a bare silicon dioxide surface of the cavity, whereas it is almost completely adsorbed on a gold-coated surface. (ii) The van der Waals force, due to the coupling of the atom with vacuum fluctuations, was observed at very long range using Rydberg states of the alkalis. (iii) With a nearly-resonant standing wave in the cavity, the optical dipole force was used to overcome the van der Waals attraction to the walls and trap sodium atoms in the center of the cavity.