Quasi-conformal transformation optics with elasto-electromagnetic metamaterials: Design algorithm

We report here a design method that is used to determine the initial shapes of elasto-electromagnetic metamaterial blocks with respect to the given shape of a hiding object when these blocks are applied to the problem of carpet cloaking. Starting from the inhomogeneous permittivity distribution of a cloak, derived using transformation optics, we use an inverse process to design the initial shape of a uniform permittivity material for an arbitrary value of Poisson's ratio in the range from -1 to 0.5. Then, by elastic compression of the initially uniform metamaterial, we obtain the inhomogeneous permittivity distribution that is required for cloaking. Our design method is then experimentally verified by measurements of the electric field profiles in smart metamaterial cloaks.