  We use time-evolution techniques for (infinite) matrix-product-states to
calculate, directly in the thermodynamic limit, the time-dependent
photoemission spectra and dynamic structure factors of the half-filled Hubbard
chain after pulse irradiation. These quantities exhibit clear signatures of the
photoinduced phase transition from insulator to metal that occurs because of
the formation of so-called $\eta$ pairs. In addition, the spin dynamic
structure factor loses spectral weight in the whole momentum space, reflecting
the suppression of antiferromagnetic correlations due to the buildup of
$\eta$-pairing states. The numerical method demonstrated in this work can be
readily applied to other one-dimensional models driven out of equilibrium by
optical pumping.
