Fundamental optical physics: The quest for zero refractive index

Fundamental optical physics: The quest for zero refractive index: "

Nature Photonics 5, 449 (2011).
doi:10.1038/nphoton.2011.172


Author: Jörg Schilling

A superlattice comprising alternating layers of negative-refractive-index photonic crystals and positive-refractive-index dielectric media has been shown to exhibit an effective refractive index of zero. Experiments show that light passing through such a material experiences no phase shift."