Excitation of quantum systems by short laser pulses: The effect of the pulse shape and durations

Abstract

We present a simple universal approach for the description of the quantum system excitation by short laser pulses in terms of the probability during the action of a pulse. Our attention is focused on the probability dependence on the pulse duration for different pulse envelopes and detunings of the carrier from the resonance frequency. We considered Gaussian, super-Gaussian, sin2 and rectangular envelopes and a Gaussian spectral profile of the excitation cross section. It is shown that the excitation probability as a function of the pulse duration is of various characters, changing from monotonic to oscillating depending on a pulse shape, a carrier frequency detuning from the resonance, and a spectral width of the cross section, in contrast to the prediction of the standard perturbation approach based on the Fermi golden rule.