Thermal fluctuations in the optical properties of dielectric and plasmonic nanomechanical metamaterials

We experimentally observe that fluctuations in metamaterial optical properties peak at the frequencies of the nanostructures’ natural mechanical modes, due to ‘Brownian’ motion. Fluctuations in flexural phonon density are the underlying mechanism for this motion, which is observed as fluctuations in optical properties reaching 1% at room temperature.