Optical metamaterials

Abstract Metamaterials are artificially engineered materials, and they exhibit properties not found in naturally occurring materials. This chapter introduces first the left-handed materials with negative refractive index and microwave structures that first exhibited this peculiar property. After discussing some unusual properties of metamaterials, like realization of perfect lens, focus is given to negative refractive index with positive permeability and permittivity. In this regard, chiral metamaterials and infinite or hyperbolic metamaterials with their properties are discussed. Plasmonic metamaterials with low loss are then described. After introducing the subject in general, attention is given to semiconductor metamaterial structures, showing negative permittivity, and having quantum system anisotropy. The concept, structure, and properties of metasurfaces, and their application in THz systems are stated. Some applications like THz modulator, and a solid-state tunable beam steering device in automotive cars are finally discussed.