Controlling polarization twisting of light resulting from surface plasmon interactions with threefold symmetric nanostructures

The design and architecture of nanostructures for the purpose of controlling and manipulating surface plasmon polariton (SPP) dynamics is currently a focal point of research. It is driven by the predicted impact that plasmonic components will have on many future technologies. In this paper, we demonstrate the first instance of plasmon-mediated polarization reorientation observed in the far field with no associated re-emission directional change. Specifically, it is demonstrated that, as a result of the interaction between SPPs and tailor-designed nanostructures of threefold symmetry characteristics, a polarization twisting of the SPP-mediated reradiated light is attained. It is shown that the dynamics of such an interaction can be controlled externally, enabling active control of the outgoing polarization orientation. In order to further understand the origin of the processes involved, Green's function based simulations of the interactions are presented and confirm that the origin of the polarization twisting can be explained via asymmetrical in-plane SPP scattering.