Metamaterials with negative refractive index

This paper presents a review of the literature data on the development and investigation of metamaterials with negative refractive index—artificial materials consisting of structural elements whose form and relative arrangement can be specified during fabrication. Intensive studies are described that were carried out in recent decades and that led to the creation in 2003 of metamaterials that demonstrate negative refractive index in the gigahertz frequency range. New trends are pointed out that have made it possible to obtain metamaterials with negative refractive index in the near-IR region.