Research Interests

Using high resolution multiple resonance excitation of molecular systems [1] we have expanded Quantum Optics from closed atomic systems to open molecular systems despite much weaker oscillator strengths and complex relaxation pathways.  Molecular systems are open in the sense that excited states have a variety of relaxation options.  The richness of molecular excitation pathways and the number of molecular interactions have made it possible to develop novel applications in this field [2] with the Autler-Townes effect as a tool.  We have demonstrated control of molecular angular momentum alignment [3], Electromagnetically Induced Transparency (EIT) [4, 5], and control of molecular quantum state spin multiplicity character [6].  We have also shown that EIT can be used to map the absolute magnitude and the internuclear distance dependence of the electronic transition dipole moment function [7].

The electric field amplitude of the control laser can be used as a “tuning” mechanism for the singlet-triplet mixing coefficients of energy levels that are weakly perturbed by the spin-orbit interaction.  Such perturbed gateway levels provide access from the singlet manifold of electronic states to the dark triplet states that cannot be reached from a singlet ground state.  This Autler-Townes effect based tuning mechanism not only controls the spin multiplicity (e.g. singlet and triplet)  character of the perturbed  pair of levels, but we have demonstrated that it can be used to control the population flow through such a gateway [8] from the singlet states to the electric dipole forbidden dark triplet states.

Our research is supported by the NSF Experimental Atomic, Molecular and Optical Physics Division