Computational Modeling of 3D Metamaterial Wire Arrays for Terahertz Operation

The computational modeling of a 3D Metamaterial beam array has been performed employing a commercially available Finite Differences Time Domain (FDTD) software package, to determine the prospective suitability of the proposed geometry in the demonstration of filters and resonators operating in the THz regime. The modeled structure comprises arrays of metallic, horizontal beams supported by vertical anchors placed on a semi-infinite silicon substrate with a refractive index of n=3.42+i0.01 with the boundary conditions considered periodic in the directions parallel to the beams and a Perfectly Matched Layer (PML) in the direction perpendicular to them. The simulations indicate a high pass filter behavior with a strong dependence on the unit cell length such that the cutoff frequency decreases as the length of the beams increase. Furthermore, due to the symmetry built in the system, the Metamaterial array is insensitive to the use of transverse electric (TE) or transverse magnetic (TM) polarization.