title: Tunable directional beaming from subwavelength metal slits with metal-dielectric composite surface gratings.
abstract: A structure for surface-plasmon-polariton mediated directional off-axis beaming with a dynamic tunability of radiation direction is proposed. The key finding in this Letter is that properly designed metal-dielectric composite grating structures surrounding subwavelength metal slit produce a dynamically tunable off-axis beaming effect with variation of the grating permittivity value. The controllability of beam direction by the grating permittivity value opens a way to develop active plasmonic devices based on the beaming effect.
authors.affiliation: National Creative Research Center for Active Plasmonics Applications Systems, Inter-University Semiconductor Research Center and School of Electrical Engineering, Seoul National University, Gwanak-Gu Gwanakro 599, Seoul, 151-744, Korea.
authors.forename: Hwi
authors.initials: H
authors.lastname: Kim
authors.forename: Junghyun
authors.initials: J
authors.lastname: Park
authors.forename: Byoungho
authors.initials: B
authors.lastname: Lee