Precision shaping of constituent elements allows construction of metamaterials with unusual physical properties. Similarly, judicious patterning of nanoscale geometries can be used to enhance coupling between distinct physical domains, such as photons and phonons in optomechanical crystals. Nanosystems combining these approaches with reconfigurability via electromechanical actuation can advance signal transduction and sensing. However, engineering devices with strong and tailorable interactions between localized modes across physical domains remains a significant challenge. Here, we couple individual optical metamolecules based on localized gap plasmon resonances to mechanical, thermal, and electrical modes in deep subwavelength volumes. Strong interactions enable broad tuning of the optical response and excite rich light-driven motion dynamics. We demonstrate, for the first time, regenerative nanomechanical oscillations mediated by thermomechanical backaction of individual plasmonic nanostructures and electromechanical injection locking of the resulting metamolecule phonon lasers. Such multiphysical nanosystems may empower smart metamaterials with applications in fast spatial light modulation, nanomechanical sensing, and tunable flat optics.
Pub Type: Journals
plasmonics, NEMS, optomechanics, phonon lasers, injection locking