Doppler-free approach to optical pumping dynamics in the 6S_1/2-5D_5/2 electric quadrupole transition of cesium vapor.

The 6S(1/2)-5D(5/2) electric quadrupole transition is investigated in cesium vapor at room temperature via nonlinear Doppler-free 6P-6S-5D three-level spectroscopy. Frequency-resolved studies of individual E2 hyperfine lines allow one to analyze the optical pumping dynamics, polarization selection rules, and line intensities. It opens the way to studies of transfer of light orbital angular momentum to atoms and the influence of metamaterials on E2 line spectra. (C) 2016 Optical Society of America