Abstract

A tunable plasmonic lens composed of a metallic array on a Titanium dioxide slab is presented. The unit cell of this structure contains a gold V-shaped nano-antenna on a uniaxial anisotropic thin film. The phase diagram of the cross-polarized scattered wave is calculated by a full-wave computational technique which uses the dyadic Green’s function obtained by an equivalent transmission line (TL) model in the spectral domain. The computed Green’s function is used in an integral equation for the effective surface electric current densities on the gold array. The resulting integral equation is then solved using the Method of Moments (MoM) with entire-domain basis functions and Galerkin test functions. A series of V-shaped nano-antennas with the different dimensions, due to the required phase discontinuities for each cell of the designed lens are selected based on the equal optical length principle. Finally, the entire system, i.e., the designed lens which is illuminated by the plane wave is analyzed using a full-wave EM solver. The numerical results show the optic axis rotation of the anisotropic thin film leads to controlling the intensity of the focal-spots.