A new beam propagation method (BPM) is developed based on a direct approximation to the propagator by its [(p-1)/<i>p</i>] Padé approximant. The approximant is simple to construct and has the desired damping effect for the evanescent modes. The method is applied to a tapered waveguide for TM-polarized waves, based on the energy-conserving improvement of the one-way Helmholtz equation. Numerical results are compared with those obtained with other variants of the BPM.
© 2002 Optical Society of America
Ya Yan Lu and Pui Lin Ho, "Beam propagation method using a [(p– 1)/ p] Padé approximant of the propagator," Opt. Lett. 27, 683-685 (2002)