  The response of conduction band electrons to a local, pulse-like external
excitation is investigated. The charge density wave packets that emerge as a
consequence of the excitation leave the interaction region with a speed close
to the initial state's band velocity, but there are also oscillations with
essentially the same frequency as that of the laser field. As a good
estimation, the excitation can also be considered as a localized,
time-dependent ponderomotive potential, leading to slowly varying current
oscillations. The role of all these effects are investigated for different
electron energies, carrier frequencies and sizes of the interaction area.
