Enhancement of the Purcell Effect by the Wire Metamaterials Formed by the Hexagonal Unit Cells

The dependence of the Purcell factor on nanowire metamaterial geometry was analyzed. Calculations made about the Purcell factor in realistic composites, operating at an optical spectral range, are provided. We applied a metamaterial, aiming to mitigate the negative effects of absorption in metals on the Purcell effect in nanowire structures. A nanowire metamaterial was treated as an anisotropic composite in the long-wavelength limit. We investigated the mode patterns of the surface waves, propagating at the boundary separating such a structure and a dielectric material, along with the position of the peak in the local density of states, for the various filling factors of the periodic structure. By calculating the frequency dependence of the Purcell factor, we showed an increase in the peak value in comparison with the conventional plasmonic structure in the (1–100 THz) frequency range. Moreover, an optimal set of the parameters, needed to obtain the two topological transitions in the frequency range under investigation, is proposed.