Hyperfine induced perturbation of the 5s19d Rydberg state of87Sr

Abstract
High-resolution two-photon spectroscopy was applied to investigate the 5s19d Rydberg level of strontium. Transitions from the 1S0 ground state to the 5s19d 3D3 state were observed for 87Sr (I=9/2), caused by local mixing between the 5snd 1D2 and 3D3 states induced by hyperfine interaction. A calculation shows excellent agreement with experiment.