Reconfigurable second-harmonic generation via plasmonic nanoslits counteracting strain-induced suppression in monolayer MoS₂.

on unpatterned Au films. Applying 1.2% compressive strain increases the SHG intensity by approximately threefold relative to the unstrained state, demonstrating effective strain-enabled modulation. Upon mechanical bending, the SHG response is reversibly modulated and remains stable after an initial preconditioning regime, retaining more than 95% of its initial intensity over repeated bending cycles. This strain-adaptive platform demonstrates robust cycling stability and provides a previously unexplored strategy for dynamically reconfigurable nonlinear metasurfaces, enabling applications in wearable sensors, tunable modulators, and compact frequency converters.