  We investigate theoretically the temporal behavior of a quantum dot under
off-resonant optical excitation targeted at fast acoustic phonon-assisted state
preparation. We demonstrate that in a preparation process driven by short laser
pulses three processes can be identified: a dressing of the states during the
switch on of the laser pulse, a subsequent phonon-induced relaxation and an
undressing at the end of the pulse. By analyzing excitation scenarios with
different pulse shapes we highlight the decisive impact of an adiabatic
undressing on the final state in short pulse protocols. Furthermore, we show
that in exciton-biexciton systems the laser characteristics such as the pulse
detuning and the pulse length as well as the biexciton binding energy can be
used to select the targeted quantum dot state.
