“…Yee's scheme was extended to the light-matter interactions with ultrashort pulse in anisotropic media for the unidimensional case in [36], and bidimensional case in [37], where a pesudo-spectral time-domain method was also discussed, along with similar splitting schemes for Bloch equations. In [38], a Maxwell-Bloch solver for two-level atomic systems was developed. A scrutiny of FDTD numerical methods based on Yee's scheme for nonlinear active materials revealed that they have limitations and restrictions to low-order accuracy, low dimensions, or only two-level atomic systems.…”