Blast waves in a paraxial fluid of light ^(a)

We study experimentally blast wave dynamics on a weakly interacting fluid of light. The density and velocity are measured in 1D 2D geometries. Using state equation arising from the analogy between optical propagation paraxial approximation hydrodynamic Euler's equation, we access hydrostatic dynamic pressure. In configuration, observe negative differential pressure after fast expansion localized over-density, which is typical signature for compressible gases. Our experimental results compared to Friedlander waveform hydrodynamical model. Velocity measurements presented configurations local speed sound, identify supersonic region fluid. findings show an unprecedented control over quantities