Analysis of the Optical Properties of Chiral Au Nanorod Stacks

We analyze the optical and chirooptical response of two Au nanorods vertically separated and with arbitrary relative in-plane orientation. The use of a simple model of Lorentzian oscillators assigned to the resonances of each individual rod allows analyzing the evolution of the optical properties of this 3D chiral system as a function of relative in-plane orientation, inter-rod separation, and rod dimensions. These results are compared with real physical structures fabricated by multiaxial thermal evaporation through nanohole masks. Despite the simplicity of the theoretical model, the obtained results reproduce the main experimental optical properties of the rod system.