Light localization in disordered metamaterials

Localization due to multiple scattering of photons in disordered electromagnetic media has triggered a recent paradigm shift in photonics, where disorder is no longer considered an unwanted disturbance on perfect periodicity, but is being used to achieve enhancement of luminescence, nonlinear optical interactions, Raman scattering and occupies a central position in random lasers. Here for the first time we extend the study of light localization to planar metamaterials. We study a metamaterial system consisting of asymmetrically-split ring (ASR) resonators that support both collective and individual modes. In such a metamaterial, a high-quality subradiant (trapped) modes can be excited that corresponds to a collective excitation of magnetic dipoles normal to the array plane and hence uncoupled to the magnetic field of the incident wave. This leads to a nearly-closed system, very weakly coupled to free-space, ideal for the study of localization effects.