Bulk metamaterials: Design, fabrication and characterization

Bulk metamaterials claim a lot of attention worldwide. We report about our activity and advances in design, fabrication and characterization of metal-dielectric composites with three-dimensional lattices. The nomenclature of designs exhibiting negative index behaviour in the near infrared includes the generic family of so-called nested structures. Such designs allow keeping the cubic symmetry of the unit cell along with the electric and magnetic responses showed by different parts in separate. For extraction of effective parameters we employ homemade wave propagation retrieving method free from ambiguity generic to the standard S-parameters retrieval method. Accurateness of the method is highlighted by a set of numerical checks. To fabricate smooth metal three-dimensional structures we develop an electroless chemical technique. We present the results of silver deposition on the surface of a 30-layers-thick polymer woodpile photonic crystal. Characterization of such samples before and after metal deposition in the 700 nm 1700 nm range exposes some unpredictable features like an enhanced broadband transmission, which still waits to be explained.