Extension of the unconditionally-stable four-stages split-step FDTD method to debye dispersive media

The unconditionally-stable four-stages split-step finite-difference time-domain (SS4-FDTD) method is extended to Debye dispersive media, which based on the auxiliary differential equation (ADE) formulation. Furthermore, numerical results are carried out for different Courant-Friedrichs-Lewy numbers in two-dimensional domains, which shown that the proposed method is unconditionally-stable.