Polarization optical switching between supercell states of plasmonic metasurfaces

We study, experimentally and numerically, in-plane light scattering (side scattering) and near- and far-field collective excitations in plasmonic metasurfaces consisting of periodic arrays of Au V-shaped nanoantennas. Each unit cell in these arrays includes a pair of such nanoantennas facing each other (<>). We show that, depending on the polarization of the incident light, such metasurfaces can support two types of supercells (<+ > and > +<). <+ > is a braket supercell wherein two nanoantennas of the same unit cells are coupled to each other via their plasmonic fields. When the polarization of the incident light is rotated by 90 degrees, a plasmonic conjugate supercell is formed (> +<). In this case the plasmon fields couple two V-shaped nanoantennas of the neighboring cells, supporting a geometrical and near-field coupling process different from <+ >. We show that braket and conjugate supercells support sharp infrared resonances at two different wavelengths, offering a high extinction polarization optical switching process associated with the transition between <+ > and > +<. Our results show that while <+ > supercells tend to be optically noninteracting with each other, > +< supercells can get coupled to the lattice modes, spatially extending coherent properties across the arrays. We investigate the in-plane scattering of these arrays, demonstrating how variations of the charge configuration and phase by the incident light polarization can be used to coherently control the in-plane scattering of V-shaped nanoantennas arrays.

Automated summary

In this study, in-plane light scattering and collective excitations in plasmonic metasurfaces consisting of Au V-shaped nanoantennas were investigated experimentally and numerically. It was found that the metasurfaces can support two types of supercells, with different coupling processes and resonances, depending on the polarization of the incident light.