  Optimally doped cuprate superconductors are characterized by the presence of
superconducting fluctuations in a relatively large temperature region above the
critical transition temperature. We reveal here that the effect of thermal
disorder, which decreases the condensate phase coherence at equilibrium, can be
dynamically contrasted by photoexcitation with ultrashort mid-infrared pulses.
In particular, our findings reveal that light pulses with photon energy
comparable to the amplitude of the superconducting gap and polarized in plane
along the copper-copper direction [110] can dynamically enhance the optical
response which is associated to the onset of superconductivity. We propose that
this effect could be rationalized by an effective d-wave BCS model, which
reveals that mid-infrared pulses result in a transient increase of the phase
coherence.
