Abstract

Experiments carried out recently have demonstrated that different spatial distributions of atoms such as stable rings are possible in magneto-optical traps (MOT). We have investigated the ring-shaped atomic distribution as a function of the main parameters involved in the trap: magnetic field gradient, laser intensity, detuning, misalignment and number of atoms, and compared the results with a simple theoretical model based on a coordinate-dependent vortex force¹ acting in each individual atom. We employ a MOT which captures Na atoms from the vapor contained in a heated cell.² The ring-shaped atomic distribution is obtained when the beams are properly misaligned in a plane, forming a racetrack configuration. Fig. 1 (a, b, c, d) contains the experimental results and the analytical model for the dependence of the radius of the ring as a function of different parameters.

© 1994 Optical Society of America