Gate tunable coupling of epsilon-near-zero and plasmonic modes

In this work, an active tuning of the coupling strength in a strongly coupled system comprised of a thin epsilon-near-zero material and gold nanorods as plasmonic resonators is demonstrated. A novel gating scheme is developed where an ionic liquid is employed to bias the coupled system and tune the coupling in transmission mode. A significant tuning of the coupled resonance up to 30 nm is observed by changing the bias voltages from 0 to 4.5 V. This control mechanism on strong coupling opens exciting opportunities for various disruptive applications by offering advanced control and tunability on strongly coupled systems.