We apply a three-dimensional Doppler Monte Carlo simulation to study fluctuation in magneto-optical traps with various laser beam configurations. First, the temperature and the radius of a lithium trap are calculated with the assumption of exactly counterpropagating beams. The results are compared with previously reported experimental data [Opt. Commun. <b>158</b>, 263 (1998)]. Subsequently, the role of fluctuation in the transition from a ball- to a ring-shaped spatial distribution of atoms is investigated. This transition occurs when the laser beams in the <i>xy</i> plane are progressively misaligned. Finally, the temperature of the atoms in a ring-shaped distribution is determined, and its dependence with the misalignment of the beams is analyzed.
© 2001 Optical Society of America
(020.0020) Atomic and molecular physics : Atomic and molecular physics
(020.7010) Atomic and molecular physics : Laser trapping
(140.3320) Lasers and laser optics : Laser cooling
(140.7010) Lasers and laser optics : Laser trapping
D. Felinto, H. Regehr, J. W. R. Tabosa, and S. S. Vianna, "Fluctuations in ball- and ring-shaped magneto-optical traps at low densities," J. Opt. Soc. Am. B 18, 1410-1415 (2001)