Plasmonic metamaterials based on assemblies of metallic nanoparticles (MNPs) have finely tunable optical properties, which can be tailored for different applications, from sensing to waveguiding [1], [2]. Nanorods and nanorod arrays have been widely studied both theoretically and experimentally. In addition to the transverse and longitudinal localised surface plasmon resonances (LSPR), when arranged as an array of aligned particles, a new spectrum of delocalized modes arises [3]. Coated nanorods open up an even greater range of applications, exhibiting cavity mode resonances whose wavelengths depend on the shell to diameter thickness ratio. In particular, we have focused our attention on Silicon, gold coated nanowires.
