Finite Element Time Domain Solution of Resonant Modes in Photonic Bandgap Cavities

In this paper, an efficient finite-element based time-domain propagation procedure is presented for the accurate modelling of two-dimensional photonic bandgap cavities. Through the propagation along the ‘complex’ time domain, a novel numerically efficient procedure is suggested to calculate the resonant wavelength, the quality factor and the area of the resonant mode in a very few steps of propagation. The high numerical precision of the proposed method is demonstrated through the excellent agreement of the results obtained using this method and their counterparts in the literature obtained using other numerical techniques.