Frequency-Dependent Locally One-Dimensional FDTD Implementation With a Combined Dispersion Model for the Analysis of Surface Plasmon Waveguides

The implicit finite-difference time-domain (FDTD) method based on the locally one-dimensional scheme is extended to the frequency-dependent version for the analysis of the Drude-Lorentz model. The piecewise linear recursive convolution method is introduced, in which a large time step can be utilized. Analyses of a metal-cladding optical waveguide supporting a surface plasmon polariton reveal that the present method provides wavelength responses comparable to those of the explicit FDTD, while reducing the computational time to less than 50%.