title: Dielectric lens guides in-plane propagation of surface plasmon polaritons.
abstract: In this work, we present in-plane propagation of surface plasmon polaritons (SPPs) guided by a single dielectric (Al2O3) subwavelength lens. By mounting a designed Al2O3nanoparticle on the silver film, the effective index of a silver-Al2O3interface is influenced by the particle thickness, then the phase difference between the silver-air and silver-Al2O3interface can be utilized to modulate the in-plane propagation of SPPs. We show that an elliptical Al2O3lens transforms the diffusive SPPs into a collimated beam, whose direction of propagation and beam width can be easily controlled. We also present that a triangular Al2O3lens significantly reforms the SPPs to a Bessel beam, which possesses non-diffractive and self-healing properties. Our investigation provides unique way to guide the in-plane transport of SPPs by using dielectric subwavelength elements, which may achieve potential applications in plasmonic integrated circuits.
authors.forename: Wen-Bo
authors.initials: WB
authors.lastname: Shi
authors.forename: Tian-Yong
authors.initials: TY
authors.lastname: Chen
authors.forename: Hao
authors.initials: H
authors.lastname: Jing
authors.forename: Ru-Wen
authors.initials: RW
authors.lastname: Peng
authors.forename: Mu
authors.initials: M
authors.lastname: Wang