Electrochemical Modulation of Strong Vibration-Cavity Coupling

Modulation of strong coupling has implications for on-demand reactivity, optical modulation devices, and greater understanding of molecule-cavity coupling effects. Here, we electrochemically switch the redox couple benzoquinone / dihydroquinone (BQ / dHQ) within an optical cavity. We find that the BQ carbonyl species can be reduced, under appropriate biases, resulting in the complete elimination of the Rabi splitting, the signature of strong coupling. We achieve optical signal modulation of ~100 % at frequencies near the fundamental BQ carbonyl absorption and the polariton bands, and experimentally evaluate the switching rate of such systems finding that repeated cycling degrades performance, likely due to compositional changes in the electrochemical medium during the electrochemical reactions. Cavity resonances shift over time in correlation with the change of the solvent dielectric constant during electrochemical cycling. Although this consequent detuning influences the magnitude of optical modulation a...