Fabrication of large-area patterned nanostructures for optical applications by nanoskiving

Cost-effective and convenient methods for fabrication of patterned metallic nanostructures over the large (mm²) areas required for applications in photonics are much needed. In this paper, we demonstrate the fabrication of arrays of closed and open, loop-shaped nanostructures by a technique (nanoskiving) that combines thin-film deposition by metal evaporation with thin-film sectioning. These arrays of metallic structures serve as frequency-selective surfaces at mid-infrared wavelengths. Experiments with structures prepared using this technique demonstrate that a closed-looped structure has a single dominant resonance regardless of the polarization of the incident light, while open structures have resonances that are anisotropic with respect to the polarization of the electric field. Finite-difference time-domain (FDTD) simulations reproduce the scattering spectra of these frequency-selective surfaces, provide an explanation of the wavelength of the experimentally observed resonances, and rationalize their polarization dependence based on the patterns of current induced in the nanostructures.