ENZ-metamaterial–induced perfect transparency for the highly directive plano-concave lens

Abstract We propose an ENZ-metamaterial–based transparent sandwich design consisting of periodic slits in a metal screen integrated with ENZ metamaterials for the exploration of superior transmissions. An equivalent circuit is proposed to reveal the interactions between the slit array and ENZ metamaterials when electromagnetic fields are penetrating through, and indicates that the involvement of ENZ metamaterials with the frequency dispersion behaviors can create the perfect match for total transmissions. On this basis, we further propose the design of plano-concave lens with the non-uniform ENZ metamaterial interlayer and demonstrate the superior collimation and focusing of electromagnetic fields at specific frequency points with perfect transparency. These findings may initiate the quest for building up more advanced electromagnetic devices tailored to specific applications with extreme parameter metamaterials.