Thermalization and Bose-Einstein condensation of quantum light in bulk nonlinear media
1 SISSA-International School for Advanced Studies and INFN - Via Bonomea 265, 34136 Trieste, Italy
2 INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento - Via Sommarive 14, 38123 Povo, Italy
Received: 6 May 2016
Accepted: 4 August 2016
We study the thermalization and the Bose-Einstein condensation of a paraxial, spectrally narrow beam of quantum light propagating in a lossless bulk Kerr medium. The spatiotemporal evolution of the quantum optical field is ruled by a Heisenberg equation analogous to the quantum nonlinear Schrödinger equation of dilute atomic Bose gases. Correspondingly, in the weak-nonlinearity regime, the phase-space density evolves according to the Boltzmann equation. Expressions for the thermalization time and for the temperature and the chemical potential of the eventual Bose-Einstein distribution are found. After discussing experimental issues, we introduce an optical setup allowing the evaporative cooling of a guided beam of light towards Bose-Einstein condensation. This might serve as a novel source of coherent light.
PACS: 42.65.-k – Nonlinear optics / 67.10.Fj – Quantum statistical theory / 64.70.fm – Thermodynamics studies of evaporation and condensation
© EPLA, 2016