OPTICAL MIXING OF RYDBERG ANGULAR MOMENTA

When optical frequency fields are used to couple a ground state to a R ydberg state, the resonant dipole coupling is to a low angular momentu m state. Higher angular momentum states are typically thought not to p lay a role in the excitation. The extremely large dipole matrix elemen ts coupling Rydberg states of the same n but differing l, however, all ow optical fields of modest strengths to produce Rabi frequencies larg er than optical frequencies. We demonstrate that these optical fields can therefore readily excite the higher angular momentum states, and w e examine the consequences of this coupling.