Dynamics of two-level systems irradiated by sub-one-cycle laser pulses

Transitions in a two‐level system irradiated by linearly polarized cosine and sine waveform sub‐one‐cycle pulses are considered. The probabilities of transition after the end of laser pulse are derived numerically as functions of two dimensionless variables: Eτ and Fτ , where τ is the pulse duration, E is the energy distance between considered levels, and F is the dipole matrix element of the transition (all quantities are presented in atomic units). We derive also the dipole moment of a two‐level system after the pulse termination as a function of the same dimensionless parameters. There is no significant dependence of dipole moment and inversion population on the cosine, or sine waveform. (© 2007 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)