title: Self-collimation and focusing effects in zero-average index metamaterials.
abstract: One dimensional photonic crystals combining positive and negative index layers have shown to present a photonic band gap insensitive to the period scaling when the volume average index vanishes. Defect modes lying in this zero-n gap can in addition be obtained without locally breaking the symmetry of the crystal lattice. In this work, index dispersion is shown to broaden the resonant frequencies creating then a conduction band lying inside the zero-n gap. Self-collimation and focusing effects are in addition demonstrated in zero-average index metamaterials supporting defect modes. This beam shaping is explained in the framework of a beam propagation model by introducing an harmonic average index parameter.
authors: LASMEA UMR-CNRS 6602 Université Clermont-Ferrand II, Aubiere, France. Remi.Polles@univ-bpclermont.fr
authors: Rémi
authors: R
authors: Pollès
authors: Emmanuel
authors: E
authors: Centeno
authors: Julien
authors: J
authors: Arlandis
authors: Antoine
authors: A
authors: Moreau
mesh_terms: D003198:Computer Simulation; D008027:Light; D008420:Manufactured Materials / Q000032:analysis*; D008956:Models, Chemical; D012031:Refractometry; D012542:Scattering, Radiation