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.
© 2009 Optical Society of America
Optics at Surfaces
Original Manuscript: June 2, 2009
Revised Manuscript: July 24, 2009
Manuscript Accepted: July 26, 2009
Published: August 19, 2009
Hwi Kim, Junghyun Park, and Byoungho Lee, "Tunable directional beaming from subwavelength metal slits with metal–dielectric composite surface gratings," Opt. Lett. 34, 2569-2571 (2009)