Directional coupling and focusing surface plasmon polaritons controlled by arbitrary spin of light

TL;DR

This paper introduces a novel device that controls surface plasmon polaritons' direction and focus based on arbitrary spin of light, enabling advanced polarization-based applications in nanophotonics.

Contribution

The work presents a new device capable of directional coupling and focusing of surface plasmon polaritons for any input light spin, surpassing traditional polarization control methods.

Findings

Achieves high polarization extinction ratio for arbitrary spin input

Enables polarization sensing and splitting

Facilitates polarization-multiplexed near-field imaging

Abstract

Surface plasmon polaritons have attracted varies of interests due to its special properties, especially in the polarization-controlled devices. Typically, the polarization-controlled devices include directional coupling, focusing lens and plasmonic vortex lens, and almost all of them are controlled by the input circularly polarized light or the linearly polarized light. We present a novel device that realize the functions of directional coupling and focusing with high polarization extinction ratio for arbitrary spin of input light. This device offers opportunities for polarization sensing, polarization splitting and polarization-multiplexed near-field images and surface plasmon holography in the future.