Multichannel transient spectra and time resolved photo-electron spectra have become standard measurements for the analysis of photophysical and photochemical processes. To extract the dynamics from the experimental data one needs to find a model that describes the system most accurately. From this model a parametrized fit function is derived. A set of adequate parameter values can be found by either fitting selected time traces or by modelling whole "bands" of the spectro-temporal surface.

While the former method is very often subject to wavelength dependent parameter variations, the latter approach generates an averaged set of parameters that is optimal for the whole spectral range. Being aware of "problematic" effects like spectral narrowing or spectral shifting one can use global analysis to extract a consistent set of parameters.

We developped TSA-Lab which is a computer program package for fitting time-resolved pump-probe transients and photoelectron spectra. The power of this program lies in a highly versatile interface that allows for easy visualisation of complex experimental data and the results of the fit. The program has been written completely in LabVIEW(TM) and implements a Levenberg-Marquardt fitting algorithm and the global analysis routine presented by Fita et al. [P. Fita, E. Luzina, T. Dziembowska, C. Radzewicz, A. Grabowska, J. Chem. Phys. 125, 184508 (2006)].