Optimum Parameter Selection for Accurate FDTD Simulations in Dispersive Media

This work aims at enhancing the accuracy of finite-difference time-domain (FDTD) models when dispersive media are involved. Focusing on the case of Lorentz dispersion, we propose the proper modification of the model’s constitutive parameters, so that the numerical-dispersion flaws are mitigated. The discretization scheme’s dispersion relation is used for the extraction of suitable error functions, which are essential for determining the new material constants via the solution of minimization problems. The proposed approach is assessed through both theoretical and numerical studies, affirming the positive impact and advantages of incorporating the modified materials in dispersive FDTD simulations.