Fast Analysis of Metasurfaces Composed of Asymmetric Scatterers Using FDTD With Anisotropic Surface Susceptibility Model

The finite-difference time-domain (FDTD) method with surface susceptibility model (SSM) had been developed to accelerate metasurfaces analysis before. However, the previous work is confined to symmetric scattering elements. This letter thus generalizes the FDTD-SSM algorithm to analyze metasurfaces composed of asymmetric scattering elements. We first classify the problem and then derive and present the corresponding FDTD-SSM equations. The validity and efficiency of the proposed FDTD-SSM algorithms are demonstrated through numerical experiments.