Prethermalization in a quenched one-dimensional quantum fluid of light: Intrinsic limits to the coherent propagation of a light beam in a nonlinear optical fiber

摘要: We study the coherence properties of a laser beam after propagation along one-dimensional lossless nonlinear optical waveguide. Within paraxial, slowly-varying-envelope, and single-transverse-mode approximations, quantum light field in medium is mapped onto Gross-Pitaevskii-type evolution closed system many interacting photons. Upon crossing entrance back faces waveguide, photon-photon interaction parameter undergoes two sudden jumps, resulting pair quenches system's Hamiltonian. In weak-interaction regime, we use modulus-phase Bogoliubov theory dilute Bose gases to describe fluctuations fluid predict that correlations typical prethermalized state emerge locally their final form propagate light-cone way at speed sound photon fluid. This peculiar relaxation dynamics, visible exiting results loss long-lived light.