Polarization-controlled generation and superposition of surface plasmon polariton vortices with a plasmonic metasurface

Abstract

Optical vortex that carries orbital angular momentum has shown great potential in various applications, including high-density optical communication, quantum information, and manipulation of small particles. Here, an approach to design a plasmonic metasurface that can control both the generation and superposition of surface plasmon polariton (SPP) vortices is proposed and demonstrated. Under circularly polarized light incidence, the SPP vortices with different topological charges can be generated depending on the spin of the incidence, and the superposition state can be achieved when the polarization of incident light turns to linear polarization. Furthermore, it is demonstrated that the superposition of SPP vortices can be accurately controlled by the polarization states of the incidence. This proposed approach is quite versatile for generating and controlling SPP vortices and provides a feasible way to design miniaturized photonic devices for on-chip optical micromanipulation, sensing, and other related applications.