Time-Domain BPM Technique for Modeling Ultra Short Pulse Propagation in Dispersive Optical Structures: Analysis and Assessment

In this work, the time-domain beam propagation method (TD-BPM) has been extended to model ultra-short optical pulse propagation in structures containing material dispersion. The method uses Pade approximant to solve the one-way non-paraxial wave equation. The TD-BPM is implemented and analyzed using several iterative numerical techniques to model the propagation of ultra-short pulses in optical waveguide structures containing Lorentz material dispersion. Systematic accuracy and efficiency assessment, compared to the FDTD, showed that the longitudinal and the temporal steps sizes can be a number of order of magnitude larger than the FDTD step sizes. It is concluded that the TD-BPM is suited for long dispersive dielectric structures interaction of short and ultra-short pulse propagation.