Fast Calculation of Cavity-Mode Characteristics of Photonic Crystal Cavities

A fast approach based on effective index perturbation method is proposed to evaluate the intrinsic characteristics of photonic-crystal-slab-based microcavity with two-dimensional finite-difference time-domain (2-D FDTD) technique. For two widely used single defect structures, less than 2% computational error was obtained in calculating the defect mode frequencies. Accurate prediction of cavity modal properties and resonant peak frequencies is feasible based on 2-D FDTD simulation by adjusting the effective index to match the dielectric band edge for donor-like defect mode. The correlation between the modified effective index and the cavity (lasing) mode with the highest quality factor Q offers an efficient tool in the design of defect mode based photonic crystal microcavities