Numerical modeling of pulse propagation through a double-negative metamaterial with adjacent absorptive and gain Lorentz dispersions: A comparison

The state-of-the-art time-domain numerical techniques, the finite-deference time-domain (FDTD) method and the pseudospectral time-domain (PSTD) method, are applied to simulate the physical propagation process of a pulse through a double-negative metamaterial with adjacent absorptive and gain Lorentz dispersions. The algorithmic feasibility and modeling accuracy of the two numerical methods combined with the common techniques for Lorentz dispersion implementation are demonstrated from the obtained simulation results and compared with the analytical solution. It is shown that the FDTD method with material parameters averaged at the slab's two interfaces works better than that without averaging and also better than the case of PSTD method with the same time and space discretization parameters. The proposed techniques are useful for the ultra-accurate modeling of pulse interaction with metamaterials.