Magnetic field-induced modification of selection rules for Rb D2 line monitored by selective reflection from a vapor nanocell

Magnetic field-induced giant modification of the probabilities of five transitions of 5S(1/2), F-g = 2 -> 5P(3/2), F-e = 4 of Rb-85 and three transitions of 5S(1/2), F-g = 1 -> 5P(3/2), F-e = 3 of Rb-87 forbidden by selection rules for zero magnetic field has been observed experimentally and described theoretically for the first time. For the case of excitation with circularly-polarized (sigma(+)) laser radiation, the probability of F-g = 2, m(F) = -2 -> F-e = 4, m(F) = -1 transition becomes the largest among the seventeen transitions of Rb-85 F-g = 2 -> F-e = 1, 2, 3, 4 group, and the probability of F-g = 1, m(F) = -1 -> F-e = 3, m(F) = 0 transition becomes the largest among the nine transitions of Rb-87 F-g = 1 -> F-e = 0, 1, 2, 3 group, in a wide range of magnetic field 200-1000 G. Complete frequency separation of individual Zeeman components was obtained by implementation of derivative selective reflection technique with a 300 nm-thick nanocell filled with Rb, allowing formation of narrow optical resonances. Possible applications are addressed. The theoretical model is well consistent with the experimental results.