Turbulent dynamics in a two-dimensional paraxial fluid of light

Turbulence in quantum fluids has, surprisingly, a lot in common with its classical counterpart. Recently, cold atomic gases has emerged as a well-controlled experimental platform to study turbulent dynamics. In this work, we introduce a system to study quantum turbulence in optics, with the major advantage of having access to a wide range of characterization tools available for light fields. In particular, we report the temporal dynamics of density and phase and we show the emergence of isotropy in momentum space and the presence of different scaling laws in the incompressible kinetic energy spectrum. The microscopic origin of the algebraic exponents in the energy spectrum is discussed by studying the internal structure of quantized vortices within the healing length and their clustering at larger length scales. These results are obtained using two counterstreaming fluids of light, which allows for a precise preparation of the initial state and the in situ measurement of the compressible and incompressible fluid velocity.