Recursive implicit time domain technique for modeling dispersive materials

Abstract

Short pulse propagation inside a frequency-dependent Debye medium is studied by developing an algorithm for the solution of wave equation using recursive time-domain beam propagation method. Being an implicit and recursive technique, it is compared with other existing similar techniques, such as recursive finite difference time domain and time domain beam propagation method. The developed technique avoids matrix inversion though a considerable numerical dispersion is observed. The numerical dispersion is assessed and superseded through an empirical relation. The prominent benefit of this technique is that it is stable for multi-pole Debye medium even at high time steps with relaxed mesh-grid.