Space-time couplings at the DRACO laser

The effect of spatio-temporal distortions in the DRACO laser potentially leads to pulse-front tilts in the laser focus on the order of tens of degrees. It is emphasized, that for controlling the focal pulse-front tilt, it is not only necessary to analyze angular dispersion, but additionally spatial and group delay dispersion. A qualitative picture of the space-time couplings is presented and quantitatively discussed at the example of an imperfectly aligned DRACO compressor. The results suggest that the focal pulse front tilt is currently unknown and that more precise measurements of both spatial and group delay are required.