Low loss planar negative index metamaterials for the mid-infrared based on frequency selective surfaces

In this paper a planar metamaterial platform based on frequency selective surface (FSS) technology is presented along with a design methodology for realizing low loss negative index metamaterials (NIM). FSSs are periodic metallic screens supported by dielectric substrates and/or superstrates. Although they naturally act as electromagnetic filters, FSSs have also been used extensively as metamaterials such as artificial magnetic conducting (AMC) surfaces, metaferrites, and zero index metamaterials (ZIMs). A design example for a low loss FSS NIM was presented that is optimized by a genetic algorithm (GA) for mid-infrared (IR) operation at a wavelength of 3 mum.