Nanoscale plasmonic mode conversion mediated by localized surface plasmon in metal-dielectric-metal waveguide link

During the past few decades, the study on plasmonics has dramatically increased and become broaden to give us a potential tool for nanophotonic engineering by its intrinsic nanoscale light localization. Here, the conversion of surface plasmon polariton modes propagating in metal-dielectric-metal (MDM) waveguide, as well as excitation and modulation, is considered as one of main concepts in plasmonics. In this Letter, we proposed a subwavelength plasmonic mode conversion between symmetric and antisymmetric modes by using localized surface plasmon resonance in disk resonator coupled to the MDM waveguide link. These devices have a nanoscale footprint of about 500×500 nm2 with a high conversion efficiency of more than 80%. Our suggestions will expand applications of nanoplasmonics and be promising for the development of next generation photonic information technology.