Topological Dislocations for Plasmonic Mode Localization in Arrays of Nanoscale Rectangular Au Apertures: Implications for Optical Communications

We study the localization of plasmonic modes on topological dislocations obtained by an abrupt change in the geometry of unit cells in a plasmonic metasurface comprised of a nanoscale array of rectangular apertures. We experimentally demonstrate mode localization in line defects and point singularities in the topology. These results are confirmed by numerical simulations of the near field distributions along the topology boundaries. We present structures with line dislocations supporting dark and bright modes. Moreover, we show that in structures with point dislocations the localization strength can be further manipulated by modifying the topological order of the structure.