Rich Broadband Chiral Behavior in Low-cost Plasmonic Nanostructures

Plasmonic nanostructures with broken symmetry have been proposed for the control of the circular polarization at the nanoscale, important for applications spanning from chiral sensing to circularly polarized nanosources. We recently demonstrated that the low-cost self-assembling nanosphere lithography, combined with tilted metal deposition, opens new possibilities for the design and fabrication of chiral nanostructures. Starting from polystyrene nanospheres (PNS) covered by asymmetric metallic shell, we measured chirality in absorption at 633 nm [1]. We discovered that the nanohole array (NHA) formed due to the shadow, can exhibit chiral properties in a broad near-infrared range [2] , [3].