An Effective FDTD Method for Multiscale Problems

In view of the fact that the traditional finite-difference time-domain (FDTD) method needs to satisfy the CFL condition and the explicit unconditionally stable FDTD (US-FDTD) method is difficult to solve eigenvalues and eigenvectors of the large-scale system matrix, the hybrid algorithm is applied to deal with multi-scale problems in this paper. The explicit US-FDTD method is used in the fine grid area, and the traditional FDTD method is adopted in the remaining calculation area, then the field at the boundary of the region is modified. After all, the entire calculation adopts a uniform large time step. Numerical result shows the effectiveness of the hybrid algorithm.