The Extraordinary Transmission through Periodic Metallic Mesh and Archimedean Spiral Hole Arrays

The extraordinary light transmission of two-dimensional rectangular metallic meshes is experimentally demonstrated. The results are explained by orthogonally superimposed one-dimensional gratings. For wavelengths that are much larger than the metal strip period, the transmission spectrum of the traditional wire-grid polarizer could be modified by interconnecting wires between the strips. It performs a special filter with a stop band from excited surface current along the additional wires that causes extra resonating modes of the individual structures. The extraordinary transmission of spiral resonators is also experimentally and numerically demonstrated. It is observed that both suface plasmon modes and shape resonance modes will contribute to the enhanced transmission. The shape resonance mode is polarization dependent and will induce giant specific rotatory power. This structure gives rise to a full modulation of polarization states by a single structured metal thin film.