  We experimentally explore the rich variety of nonlinear coherent structures
arising in a turbulent flow of superfluid light past an obstacle in an
all-optical configuration. The different hydrodynamic regimes observed are
organised in a unique phase diagram involving the velocity of the flow and the
diameter of the obstacle. Then, we focus on the vortices nucleated in the wake
of the obstacle by investigating their intensity profile and the dependence of
the radius of their core on the healing length. Our results pave the way for
further investigations on turbulence in photon superfluids and provide
versatile experimental tools for simulating quantum transport with nonlinear
light.
