FULL HYDRODYNAMIC MODEL OF NONLINEAR ELECTROMAGNETIC RESPONSE IN METALLIC METAMATERIALS (Invited Paper)

Abstract

Applications of metallic metamaterials have generated significant interest in\nrecent years. Electromagnetic behavior of metamaterials in the optical range is\nusually characterized by a local-linear response. In this article, we develop a\nfinite-difference time-domain (FDTD) solution of the hydrodynamic model that\ndescribes a free electron gas in metals. Extending beyond the local-linear\nresponse, the hydrodynamic model enables numerical investigation of nonlocal\nand nonlinear interactions between electromagnetic waves and metallic\nmetamaterials. By explicitly imposing the current continuity constraint, the\nproposed model is solved in a self-consistent manner. Charge, energy and\nangular momentum conservation laws of high-order harmonic generation have been\ndemonstrated for the first time by the Maxwell-hydrodynamic FDTD model. The\nmodel yields nonlinear optical responses for complex metallic metamaterials\nirradiated by a variety of waveforms. Consequently, the multiphysics model\nopens up unique opportunities for characterizing and designing nonlinear\nnanodevices.\n