Light Manipulations with Metasurfaces in Visible and Infrared Spectrum: Asymmetric Transmission and Tunability with Phase Change Materials

Metasurfaces are two dimensional planar photonic structures, which were recently proposed to alter amplitude, phase, and polarization of the light. Plasmonic and all-dielectric metasurfaces are two different types of structures with comparable advantageous and drawbacks. Three-dimensional nano array of trapezoidal shaped aluminium on a sapphire substrate is designed to construct metasurface for altering the optical behaviour of oppositely propagating light. We show that broadband and polarization independent asymmetric light propagation mechanism in metasurface configuration is feasible in the visible spectrum. The underlying physical concept is associated with the Wood Rayleigh Anomaly such that different number of higher order modes appear upon oppositely incident light. Introducing vanadium dioxide as phase change material into the metasurface structure allows dynamic control over the transmitted light within the mid-infrared spectrum. Proposed structure can be fabricated with the current nano and micro fabrication techniques and can be utilized in smart front IR windows for protecting delicate sensors used for imaging and target detecting systems.