In Operando Reconfigurable Exciton–Plasmon Coupling via Strain Engineering

ABSTRACT Research on exciton‐plasmon coupling with two‐dimensional transition metal dichalcogenides (2D TMDs) has gained significant attention in nanophotonics, enabling ultrasensitive sensors, optical switches, and low‐threshold nanolasers. The atomic thickness of 2D materials permits substantial deformations without structural failure, establishing strain engineering as a powerful strategy for dynamic modulation of exciton resonance. Nevertheless, strain engineering in TMD‐plasmon hybrid systems remains to be explored. Here, we demonstrate in operando reconfigurable exciton‐plasmon coupling in tungsten diselenide (WSe 2 ) monolayers integrated within plasmonic nanocube‐on‐mirror (NCoM) cavities. Applying tensile strain induces a redshift in exciton resonance (∼85 meV/% strain). When coupled to NCoM nanocavities, strain engineering dynamically modulates exciton‐plasmon detuning, facilitating real‐time control of coupling dynamics. The achieved Rabi splitting reaches ∼56 meV for monolayers and continues to increase with bilayers. This work establishes strain engineering as a new method for actively tunable exciton‐plasmon hybrid systems and reconfigurable optoelectronic devices.