Angular Momentum Orientation in Molecules Using the Autler-Townes Effect

We report an experimental demonstration of state selective molecular angular momentum orientation using dressed states created by a strong cw control laser. Our results show that the M-dependent Rabi frequency of the Autler-Townes effect for circular polarization allows for M-state selective molecular angular momentum orientation, where M is the projected angular momentum onto a lab fixed axis. Our results also show the square-root relationship between the splitting of adjacent M-levels and the power of the control laser, and thus the requirement for a strong control field to achieve M-state selectivity. The effect was observed using Li₂ molecules and a combination of left- and right-handed circularly polarized lasers.