Phase Manipulation of Electromagnetic Waves with Metasurfaces and Its Applications in Nanophotonics

Abstract Relative to conventional phase‐modulation optical elements, metasurfaces (i.e., 2D versions of metamaterials) have shown novel optical phenomena and promising functionalities with more compact platforms and more straightforward fabrication processes. With the ability to generate a spatial phase variation, optical wavefronts can be manipulated into arbitrary shapes at will, enabling new phenomena and integrated ultrathin optical devices to be explored. This review is focused on recent developments regarding phase manipulation of electromagnetic waves with metasurfaces. Starting from their underlying physics for realizing full 2π phase manipulation, an overview of the applications of such metasurfaces in nanophotonics is discussed, concluding with a discussion of future prospects in this field.