Piekarski Clara, Liu Wei, Steinhauer Jeff, Giacobino Elisabeth, Bramati Alberto, Glorieux Quentin
Laboratoire Kastler Brossel, Sorbonne Universit, CNRS, ENS-PSL Research University, Collège de France, Paris 75005, France.
Department of Physics, TechnionIsrael Institute of Technology, Technion City, Haifa 32000, Israel.
Phys Rev Lett. 2021 Jul 9;127(2):023401. doi: 10.1103/PhysRevLett.127.023401.
We implement Bragg-like spectroscopy in a paraxial fluid of light by imprinting analogues of short Bragg pulses on the photon fluid using wavefront shaping with a spatial light modulator. We report a measurement of the static structure factor, S(k), and we find a quantitative agreement with the prediction of the Feynman relation revealing indirectly the presence of pair-correlated particles in the fluid. Finally, we improve the resolution over previous methods and obtain the dispersion relation including a linear phononic regime for weakly interacting photons and low sound velocity.
