Design and Applications of Spatially-Dispersive Phase-Gradient Metasurfaces

In this work, we explore the design of spatially-dispersive gradient metasurfaces able exhibiting different phase profiles as the angle of incidence changes. Differently from earlier designs, characterized by an intrinsically-weak spatial-dispersion, here the angular selectivity of the individual Huygens cells composing the metasurface is intentionally enhanced and optimized. With a combination of analytical and numerical results, it is shown that such optimized devices exhibit different macroscopic behaviors vs. the incidence angle and offer additional possibilities compared to conventional gradient metasurfaces in many relevant applicative scenarios.