Stability Issue of the FDTD Method Based on the Iterated Crank-Nicolson Scheme

The stability issue of the recently developed iterated Crank-Nicolson (ICN) FDTD method is discussed through the analysis of an optical waveguide with high-reflection coatings. It is shown that the zero- and one-iteration techniques are unconditionally unstable, while the two-iteration one is conditionally stable as in the traditional explicit FDTD method. These results are in consistent with those obtained in the previous works where the advection equation is analyzed.