Multiphoton absorption via chirped-pulse adiabatic passage: Dynamics within the excited-state manifolds

We study the dynamics of multiphoton-absorption chirped adiabatic passage (CHIRAP) in atoms, and show that the dynamics of the excited-state fine-structure transitions can be nonadiabatic even though the optical transfer to the highly excited electronic states is fully adiabatic. Hence, care must be taken to ensure that the dynamics is selective if multiphoton-absorption CHIRAP is to be used as a pump- ing mechanism to populate very-high-lying states that can serve as the pumping levels for uv lasers. We investigate the dynamics as a function of chirp rate and field intensity in the 5s ²S_1/2→5p ²P_3/2→5d ²D_3/2,5d ²D_5/2 rubidium system, and show that selectivity can be maintained despite the near degeneracy of the ²D manifold.