Cylindrical electromagnetic concentrator with only axial constitutive parameter spatially variant

A type of electromagnetic concentrator with radial and tangential constitutive parameters as constants is proposed. Only the z component of the constitutive tensor is spatially variant, and all the constitutive parameters are nonsingular and positive, which makes it possible to construct it with two-dimensional (2D) metamaterials. The effects of loss and perturbations of parameters on the performance of the concentrator are also investigated. Finally, a simplified concentrator suitable for the case that is not sensitive to the omnidirectional scattering field is proposed. This study provides a feasible method for the fabrication of a 2D electromagnetic concentrator. (C) 2011 Optical Society of America