Plasmonic metasurfaces with high-Q nanocavities

Plasmonic metasurface nanocavities are potential candidates for many next-generation nanoscale optical applications e.g. frequency conversion. Plasmonic systems have been conventionally considered to exhibit considerable absorption losses hindering their use in applications. However, it has been recently understood that the losses can be dramatically reduced by structuring plasmonic materials to exhibit very narrow resonances and therefore high Q-factors. Here, we investigate a plasmonic metasurface array consisting of periodically arranged nanostructures that exhibits polarization-dependent resonant nanocavities, where one nanocavity has significantly high Q-factor (Q ≈ 821).