Appearance of coherent artifact signals in femtosecond transient absorption spectroscopy in dependence on detector design

Summary, in English

The appearance of coherent artifact signals in transient absorption spectroscopy employing a spectrally integrated detection system is studied. The influence of the detection design on the shape of the observed signal is detailed and the experimentally very important case, in which the shape of the coherent artifact is strongly influenced by the presence of the sample itself, is considered - leading to the situation that the artifact signal cannot be accounted for by simple comparison of the kinetics obtained for the solvent only. Finally an estimate of the relative contribution of the artifact to the overall transient absorption change is presented facilitating the interpretation of short time transients in the presence of artifact contributions and allowing to estimate the excited state absorption cross-section for a known pump-intensity dependence of the artifact signal.