  We present time-resolved scanning x-ray microscopy measurements with
picosecond photo-excitation via a tailored infrared pump laser at a scanning
transmission x-ray microscope. Specifically, we image the laser-induced
demagnetization and remagnetization of thin ferrimagnetic GdFe films proceeding
on a few nanoseconds time scale. Controlling the heat load on the sample via
additional reflector and heat-sink layers allows us to conduct destruction-free
measurements at a repetition rate of \SI{50}{\mega\hertz}. Near-field
enhancement of the photo-excitation and controlled annealing effects lead to
laterally heterogeneous magnetization dynamics which we trace with
\SI{30}{\nano\meter} spatial resolution. Our work opens new opportunities to
study photo-induced dynamics on the nanometer scale, with access to picosecond
to nanosecond timescales, which is of technological relevance, especially in
the field of magnetism.
