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

Abstract

The design and architecture of nanostructures for the purpose of controlling and manipulating surface plasmon polariton ͑SPP͒ 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 SPPmediated 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.

Surface Plasmons on Complex Symmetry Nanostructured Arrays

“…This results in the observed polarisation twisting with no associated farfield directional change. The only apparent restrictions on the polarisation rotation are found to be the initial plasmon excitation conditions [4].…”

“…One result of this is a shift from P polarised illumination at which the classical farfield SPP related minimum reflectivity occurs. Following this, the first instance of plasmon mediated polarisation reorientation observed in the farfield, with no associated directional change of the farfield light, will be described and accompanied by supporting simulations [4,5]. Finally, section 5 will deal with aspects of ultrafast dynamics of propagating SPPs.…”

“…The polarisation direction was subsequently rotated using the Fresnel rhombus in 5 • increments through a full polarisation rotation. In contrast to such a scan using the ring array, which shows minimum reflectivity for purely P polarised light, for the rotor array it [4]. Intensities are individually normalised to 1.…”

“…8, both results are in fact consistent with each other. The apparent difference originates from that fact that one measurement takes into account SPP and regular diffraction channel processes, while the other isolates the SPP excitation processes [4].…”

“…Figure 10. a&d) 10 x 10 micron field amplitude images of the incident and elastic scattered lossless SPPs, interacting with individual rotor representative structures in the N (a) and W (d) orientations [4]. b&e) Extension to interaction of SPPs with 3 by 3 arrays of the structures in the N (b) and W (e) orientations [14].…”