2015/10/31 by Pierre-Élie Larré, P. -É. Larré, Iacopo Carusotto +1 · 1 citation
Physics and Astronomy · #Beam (structure) #Classical mechanics #Coherence (philosophical gambling strategy) #Cold Atom Physics and Bose-Einstein Condensates #Hamiltonian (control theory) #Light beam #Nonclassical light #Optics #Paraxial approximation #Photon #Physics #Quantum #Quantum electrodynamics #Quantum fluid #Quantum mechanics #Quantum optics and atomic interactions #Strong Light-Matter Interactions #cond-mat.quant-gas
paper · pdf · doi:10.1140/epjd/e2016-60590-2
published as Eur. Phys. J. D 70, 45 (2016) · 19 pages, 3 figures
arxiv created 2016/01/11 · openalex publication_date 2016/03/01 · arxiv updated 2016/03/18 · openalex created_date 2021/02/01 · openalex updated_date 2026/08/05
We study the coherence properties of a laser beam after propagation along a one-dimensional lossless nonlinear optical waveguide. Within the paraxial, slowly-varying-envelope, and single-transverse-mode approximations, the quantum propagation of the light field in the nonlinear medium is mapped onto a quantum Gross-Pitaevskii-type evolution of a closed one-dimensional system of many interacting photons. Upon crossing the entrance and the back faces of the waveguide, the photon-photon interaction parameter undergoes two sudden jumps, resulting in a pair of quantum quenches of the system's Hamiltonian. In the weak-interaction regime, we use the modulus-phase Bogoliubov theory of dilute Bose gases to describe the quantum fluctuations of the fluid of light and predict that correlations typical of a prethermalized state emerge locally in their final form and propagate in a light-cone way at the Bogoliubov speed of sound in the photon fluid. This peculiar relaxation dynamics, visible in the light exiting the waveguide, results in a loss of long-lived coherence in the beam of light.