Methodologies for On‐Demand Dispersion Engineering of Waves in Metasurfaces

Dispersion is one common yet critical property of all kinds of waves. It is related to the spatial and spectral evolution of waves in structured materials. This review gives a summary of the methodologies used for the on‐demand dispersion engineering of waves in metasurfaces, which possess many unusual properties such as extremely short wavelength, diffraction‐less directional propagation, and tunable phase shift, resulting in many exciting applications with performances beyond the limitations set by traditional geometric and physical optics. Since most metasurfaces could be continuously transformed from simple thin films, the methodologies proposed here are universal and may be applied to analyze and design various functional metasurfaces.