Photonic flat band dynamics

Abstract

ABSTRACT During the last decades, researchers of different scientific areas have investigated several systems and materials to suggest new ways of transporting and localizing light. These problems are probably main goals in any search for new configurations and new emerging properties, independently of the degree of complexity of suggested methods. Fortunately, fabrication techniques in photonics have consolidated during the last decades, allowing the experimental implementation of different theoretical ideas which were neither tested nor validated. Specifically, we will focus on recent advances in the implementation of Flat Band (FB) photonic systems. FB periodical structures have at least two bands in their linear spectrum, with one of them completely flat. This implies the emergence of linear photonic states which are completely localized in space and that can be located in different regions across the lattice. This localization occurs as a result of destructive interference, what naturally depends on the particular lattice geometry. In addition, flat band systems also posses dispersive states which make possible the observation of ballistic transport as well. Therefore, FB photonic lattices constitute an unique platform for studying localization and transport, without requiring the inclusion of any sophisticated interaction/effect, rather a smart and simple geometry. Graphical abstract