Fig. 1.

Depiction of a microcavity. A large number of molecules can undergo a chemical reaction (e.g., electron-transfer-induced conformational transformation²⁴) and support a high-frequency vibrational mode that can strongly couple to a confined optical mode; these molecules are in a solvated environment (blue/purple moieties). The reaction of concern is mediated by that intramolecular mode and a collection of low-frequency modes of the solvation sphere. The optical mode is typically confined by two dielectric mirrors (blue structures) separated by a spacer that is saturated with the reaction mixture