The fourth quadrant in the e, plane: A new frontier in optics

Abstract. We review and analyze some of the novel and unique characteristics of the electromagnetic wave propagation in materials of both negative electrical permittivity and magnetic permeability, known as left-handed materials. Main steps and recent developments towards the realization and exploitation of such materials are described, while emphasis is given to the attempts for “extension ” of left-handed materials towards the optical regime. There, some of the main advances and challenges are analyzed and discussed