Modeling nonlinear responses in metallic metamaterials by the FDTD solution to Maxwell-hydrodynamic equations

A nonperturbative and universal FDTD model is proposed to investigate the nonlinear responses from metallic metamaterials. By coupling the hydrodynamic equation to the Maxwell equation, the multiphysics model enables to investigate both linear and nonlinear dynamics of free electron gas within the metallic metamaterials without any approximations and prior assumptions. Moreover, the proposed FDFD model has a potential to capture nonlocal response and other quantum effects from metallic metamaterials.