A new FDTD algorithm free from the CFL condition restraint for a 2D-TE wave

A new finite-difference time-domain algorithm, which is based on an alternating direction implicit method, is proposed in order to eliminate the Courant-Friedrich-Levy condition restraint. It is shown that the new algorithm is quite stable numerically even when the CFL condition is not satisfied. Therefore, if the cell size in the computational domain is locally much smaller than the wavelength, this new algorithm is more efficient than conventional FDTD schemes in terms of computer resources such as central processing unit (CPU) time.