Feature issue introduction: Metamaterials, Photonic Crystals and Plasmonics

With the ability to manipulate and precisely tailor the micro- and nanostructures with sizes that are comparable to or smaller than the wavelength of light, unique optical properties beyond those offered by natural materials can be achieved in various nanophotonic platforms including plasmonics, photonic crystals and metamaterials. In this feature issue, fifteen papers are included with broad coverage of the cutting-edge research in the fields ranging from optical sensing, structure-enhanced absorption, novel non-metallic plasmonic materials, structure-modified optical transmission to new types of metamaterials, topological and quantum photonics.