7. Plasmonic Metamaterials and Metasurfaces

A plasmonic metamaterial uses surface plasmons to achieve optical properties not seen in nature, while metasurfaces can be utilized to control the electromagnetic waves within one infinitely thin layer, permitting substantial advantages, such as easy fabrication, low cost, and high degree of integration. By patterning plasmonic nanostructures and engineering the spatial phase distribution within the plane, exotic optical phenomena and optical components can be achieved, including negative refraction or reflection, as well as ultrathin focusing or diverging lenses. In other words, metasurfaces tailor the in-plane phase front using an extremely thin slab consisting of judiciously designed plasmonic structures. To some extent, metasurface can be considered as the optical counterpart of frequency selective surface, which introduce prescribed phase distribution within deep subwavelength thickness, leading to exceptional changes of light propagation characteristics. This chapter will review the fundamentals, recent advances, and future perspectives in the emerging field of plasmonic metamaterials and metasurfaces as well as their applications relating to the frequency response, phase shift, and polarization state control, aiming to open up new exciting opportunities for nanoscience and nanotechnology.