Hybrid numerical–asymptotic code for dispersive-pulse propagation calculations

A fast, hybrid numerical–asymptotic algorithm for the calculation of the dynamical field evolution that is due to an arbitrary input pulse in any linear dispersive, attenuative medium is presented. The algorithm combines the numerical efficiency of the fast-Fourier-transform algorithm over a finite frequency domain that encompasses all the medium resonances with the accuracy and analytical efficiency of the asymptotic description that fully accounts for the high-frequency structure above the highest resonance that is characteristic of the dispersive medium.