Nonlinear magneto-optical rotation in the presence of a radio-frequency field.

We report measurements of nonlinear magneto-optical rotation (NMOR) for the D2 line of 87Rb atoms in an antirelaxation-coated vapor cell in the presence of a radio-frequency (rf) field. The experimental NMOR signals as a function of rf field frequency for various rf field powers are compared to a theoretical model based on the density-matrix formalism. The comparison between experiment and theory enables understanding of the ground-state atomic spin polarization dynamics, illustrated using plots of the probability distribution of the atomic angular momentum.