Strong spatial dispersion in nanostructured multilayered metal-dielectric optical metamaterials

摘要

Periodic layered metal-dielectric nanostructures are used in subwavelength imaging, invisibility cloaking, nano-lithography and optical nanocircuitry. These optical metamaterials are usually described by local effective medium model if their periods are much smaller than a wavelength. Our studies show that even under such strict conditions the metamaterials are nonlocal and exhibit strong spatial dispersion effects. The uniaxial media support two or more extraordinary waves in certain directions while the local effective model predicts only one. The strong spatial dispersion is caused by surface plasmon polariton modes at the interfaces between metal and dielectric layers.