By utilizing narrowband, continuous wave (CW) lasers and appropriately filtered laser induced fluorescence (LIF), we have benefitted from the high resolution techniques of multiple resonance laser spectroscopy.

Prof. Marjatta Lyyra co-pioneered continuous wave triple resonance spectroscopy with initial applications in high resolution molecular spectroscopy of electronic states involving large internuclear distance in collaboration with Profs. William C. Stwalley and Paul D. Kleiber at the University of Iowa. At Temple University, her research group has used this technique in molecular quantum optics studies by using the Autler-Townes (AT) effect to  demonstrate molecular Electromagnetically Induced Transparency (EIT) and more recently with Prof. Ergin H. Ahmed all-optical control of molecular angular momentum orientation by state selective population of individual magnetic sublevels.  We have also shown that the Autler-Townes effect can be used as a precision probe of the molecular transition dipole moment and its internuclear distance dependence. And we’ve more recently demonstrated all-optical control of molecular population flow through a pair of singlet-triplet levels perturbed by the spin-orbit interaction. Research on optimizing this process by the development of an all-optical spin switch is planned.