Transforming Electromagnetics Using Metamaterials

Electromagnetic metamaterials are artificially structured media with unusual electromagnetic properties that can be engineered from the radio-frequency (RF) and microwave range all the way up to optical frequencies. In its present form, the field of metamaterials is just over ten years old but has already attracted intense interest from many research groups around the globe. Suddenly, classical electromagnetism took on a fresh and exciting perspective, revealing that there are fascinating phenomena still waiting to be discovered and corresponding applications to be invented. In particular, all this excitement is associated with the notion of the macroscopic constitutive parameters, such as the permittivity and permeability. What would be possible if we were able to synthesize electromagnetic materials with arbitrarily valued constitutive parameters? The richness of this possibility becomes more evident when we recall that material parameters can be anisotropic (varying with direction) or spatially inhomogeneous (varying from point to point). Moreover, they can attain values previously not considered (i.e., negative or close to zero), and they can even mix together the electric and magnetic response of a material (chirality).