Polariton-mediated vibrational ladder climbing

Vibrational ladder climbing (VLC) happens when a dipole-active molecular vibration is promoted to a highly excited-state by undergoing multiphoton absorption. Applications of this phenomenon include chemical reaction control via optical generation of non-equilibrium molecular excited-state populations with an increased probability of undergoing bond-breaking events. In this work, we present a theoretical treatment of VLC under strong infrared coupling, where the collective vibrational polarization efficiently exchanges energy reversibly with the electromagnetic field of an optical microcavity and hybrid light-matter excitations (polaritons) emerge. We focus on the basic principles of polariton-mediated VLC, including how its efficiency can be modulated by a proper choice of mesoscopic material, and conclude by discussing potential applications to reaction dynamics control, and spectroscopy of highly-excited states.