Picometer Scale Photothermal Tuning of Plasmonic Nanocavities and Interfacial Processes.

The ability to precisely tune plasmon resonances is critical for advancing nanophotonic and sensing technologies. In this work, we exploit the photothermal effect to achieve picometer-level tunability of plasmon resonances in nanorod-on-mirror nanocavities, using polyelectrolyte (PE) layers as dielectric spacers. The plasmon-induced thermal response of these soft materials allows real-time adjustment of the nanocavity, unlike stable inorganic spacers like aluminum oxide.