Positional Dependence of Mode Detection in FDTD based Photonic Crystal Simulations

We have developed an algorithm for evaluating the accuracy and reliability of photonic crystal simulations, and used this to analyze the influence of excitation and detector placement in FDTD simulations. We generate a map of locations where mode detection fails, and show that this is equivalent to a map of the node densities of the system. In addition to the expected high nodal densities at the symmetry points of the system, we find more difficult to characterize patterns of high nodal density for the higher order modes. Based on the observed behavior we are able to provide concrete suggestions for the optimal detection and excitation of modes in FDTD simulations of photonic crystal systems.