Low-index metamaterial designs in the visible spectrum

Low-index metamaterial designs in the visible spectrum that are impedance matched to free space are presented. The unit cell of the periodic metamaterial design incorporates a magnetic resonator and silver meshes for respective control of the effective permeability and permittivity. A genetic algorithm is employed to optimize the metamaterial design to achieve a desired set of values for the index of refraction and the intrinsic impedance. Two example GA optimized designs are provided which target the important special cases of a zero and unity index of refraction.