Tuning Metasurfaces with Phase Change Materials

The possibility to reversibly modify the optical properties of plasmonic nanorod arrays by phase change materials is investigated. Three different gold (Au) nanorod arrays are fabricated on thin films of vanadium dioxide. The sensitivity of the two nanorod plasmonic modes to the thermally induced phase transition is explored and found to be greatest for the transverse mode. We demonstrate that the reflectance properties of gold nanorod arrays can be reversibly modified in the spectral range from 500 nm to 1 µm. Moreover a blue shift by 40 nm of the transverse mode scattering wavelength is observed. Our results render VO 2 thin films and nanostructures as a promising route towards the development of fine optical tuneable plasmonic nanoantennas and metamaterials in the near-infrared and visible spectral range.