Abstract

Light interacts with a resonant medium by forming polaritonic waves. These are mixed excitations of the electromagnetic field (photons) with quasiparticles related to material resonances. At frequencies lower than the electron plasma frequency, only surface plasmon polaritons (SPPs) have usually been considered, since electric fields do not significantly penetrate metals over more than the skin-depth [1]. Here we show that plasmonic nanorod metamaterials with hyperbolic dispersion support bulk plasmon-polariton waves below an effective plasma frequency, an effect due to the anisotropic character of the polaritonic dispersion. The behavior of bulk plasmon-polaritons in a planar slab of metamaterial is studied both experimentally and theoretically.

© 2015 IEEE