Murad Abuzarli
LKB SU Paris - murad.abuzarli@lkb.upmc.frBlast wind is a special type of shock waves characterized by a negative differential pressure tail following the shock front. It is, for example, responsible for the presence of glass pieces within the building after an explosion inside an edifice. We report a direct observation of the blast wind in an analogue optical superfluid, in which the repulsive photon-photon interactions stem from the Kerr effect in a hot Rb vapor cell. Interestingly, the blast wind is present in the case of a 2D perturbation and absent in the 1D geometry, in agreement with the classical prediction. In a more recent experiment we study the propagation of a partially spatially coherent state of light in a Kerr medium mimicking the evolution of an interacting 2D BEC with thermal fluctuations. According to theory, the spatial coherence function shows universal algebraic correlations upon evolution in time within the light cone of the Bogoliubov quasiparticles, analogous to the case of 2D BECs.
Related paper: https://iopscience.iop.org/article/10.1209/0295-5075/134/24001