Chiral effects in low-cost plasmonic arrays of elliptic nanoholes
In this work we present an approach to induce chiral effects in well-known plasmonic nanohole arrays with triangular unit cell. Arrays with circular nanoholes in metals can exhibit interesting light-matter interaction mechanisms such as surface plasmon polaritons and extraordinary optical transmission. Moving from circular to elliptical shape and tilting the ellipse away from the lattice symmetry lines, a symmetry breaking induces a different absorption of the circularly polarized light of opposite handedness, i.e. circular dichroism.