On the propagation of short optical pulses in a linear dispersive medium with absorption

A very accurate numerical algorithm based on the Laplace transform is used to describe the field evolution of ultrashort Gaussian-modulated pulses in a single resonance Lorentz medium. The results are compared with previously published numerical results by I. Christov (see ibid., vol.24, p.1548-53, 1988) in which a simple Taylor series expansion of the input pulse spectrum about the carrier frequency is used to explain the observed pulse dynamics. It is shown, by numerical Laplace transform analysis, that these previously published numerical results are inaccurate and that the first few terms of the Taylor series expansion technique about the carrier frequency do not properly explain the physically correct dispersive pulse evolution properties for rapid rise time pulses. In response to the comments the original author recalculated the dispersive propagation of femtosecond optical pulses by using different numerical methods