Abstract:We investigate the effect of dielectric coating on the optical resonance of metallic bowtie nanoantennas, both theoretically and experimentally. The resonance wavelengths of the nanostructures measured by means of dark-field scattering spectroscopy are in excellent agreement with our theoretical calculations. The resonance wavelength is redshifted as the thickness of the coating layer increases, which is attributed to a longer effective optical path due to the larger refractive index of the coating than that of the air.
