Full three-dimensional wavelength-scale plasmomechanical resonator

Plasmomechanical systems have received considerable interest in mediating the strong interaction between the optical field and mechanical motion. However, typical plasmomechanical systems based on mechanical oscillators that are significantly larger than the wavelength of light do not take full advantage of the optical field concentration beyond the optical diffraction limit of the employed plasmonic resonators. Here we present a full three-dimensional wavelength-scale plasmomechanical resonator consisting of a plasmonic nano-antenna and a hydrogen silsesquioxane nano-wall. The experimental results demonstrated the precise detection of longitudinal mechanical oscillation on a picometer scale, and we investigated the tunability and thermoelastic effect of the mechanical resonance.