Journal of Physics B Atomic and Molecular Physics
Optical-optical double resonance in barium
Jörg Neukammer, Herbert H. Rinneberg
Abstract
Using two CW dye lasers barium Rydberg states were populated by stepwise two-photon absorption via the 6s6p 1 P 1 intermediate level. Monitoring the transmission of the first laser beam, tuned to the resonance line, and scanning the second laser across the upper atomic transition, a greatly enhanced signal was observed. Taking optical pumping into account, a simple rate equation model can quantitatively describe the increase in sensitivity. This technique was applied to measure the hyperfine structure of the 6s15d 1 D 2 Rydberg state in barium.