Coupling effect of magnetic polariton in perforated metal/dielectric layered metamaterials and its influence on negative refraction transmission

The optical propagation properties and magnetic polariton behaviors in perforated metal/dielectric layered structures are numerically investigated at near-IR region. A developed three-metal-layer (TML) structure is specially inspected as a simple case. Strong coupling effect of magnetic polariton is discovered in this system, which explains why TML structure reveals better negative-refraction property than the reported double-metal-layer (DML) structure. A clear LC-circuit model is presented to describe the physical mechanism of this coupling effect of magnetic polaritons. Detailed results show that the thickness of metal layer influences the transmission greatly and an optimum value is found.