Autler-Townes splitting and the AC Stark effect in nonpolar molecules: Prospects for all-optical alignment

This paper describes an extension of the familiar coherence effects from atomic systems to the molecular regime. Such effects are inherent in the interaction of multiple laser fields with molecular systems. We have observed Autler-Townes splitting and the AC Stark shift in diatomic Lithium using the continuous wave all-optical triple resonance (AOTR) techniques. By using the Autler-Townes effect, we have partially resolved the magnetic sublevels of a molecular rovibrational level in a Doppler broadened sample, allowing all-optical alignment of the angular momentum in excited states of nonpolar molecules. The Autler-Townes effect in a molecular system extends the rovibrational state selectivity of the AOTR excitation technique to magnetic sublevels.