Enhanced light-assisted-collision rate via excitation to the long-lived 5S1/2-5D5/2 molecular potential in an 85Rb magneto-optical trap

We report measurements of a significant increase in the two-body loss rate in an 85Rb magneto-optic trap (MOT) caused by the addition of light resonant with the 5P3/2-to-5D5/2 transition (776 nm) in Rb. Exposure to the additional light resulted in up to a factor of 5 decrease in the steady-state number of atoms in the MOT. This loss is attributed to more than an order of magnitude increase in the light-assisted collision rate brought about by the 776-nm light. By measuring the intensity dependence of the loss rate, the loss channel was identified to be the relatively long-lived 5S1/2-5D5/2 molecular potential.