Plasmonics–mine the gap: opinion

Abstract

Gap plasmon structures could enable future ultrafast communication by allowing simultaneous nanoscale integration of electromagnetic waves, nonlinear and optical-electrical conversion, and providing a critical element often overlooked in this context: electrical contacts. Here, the fundamental limit of these structures is discussed, and it is argued that the conventional concept of “smaller is better" for higher confinement is not true when the loss is considered, but few nanometer gaps will be required to give the best performance. Overall, to achieve widescale adoption, plasmonics will likely have to combine forces with emerging CMOS-like nanophotonics.