Cosine-Gauss Plasmon Beam: A Localized Long-Range Nondiffracting Surface Wave

Abstract

A new surface wave is introduced, the cosine-Gauss beam, which does not diffract while it propagates in a straight line and tightly bound to the metallic surface for distances up to $80\mu \mathrm{m}$. The generation of this highly localized wave is shown to be straightforward and highly controllable, with varying degrees of transverse confinement and directionality, by fabricating a plasmon launcher consisting of intersecting metallic gratings. Cosine-Gauss beams have potential for applications in plasmonics, notably for efficient coupling to nanophotonic devices, opening up new design possibilities for next-generation optical interconnects. DOI: http://dx.doi.org/10.1103/PhysRevLett.109.093904 © 2012 American Physical Society