https://doi.org/10.1051/epjconf/202328706024
Thermalization of light waves in multimode optical fibers: Negative temperatures equilibrium states and the role of disorder - INVITED
1 Université de Bourgogne, Laboratoire Interdisciplinaire Carnot de Bourgogne, Dijon, France
2 CMAP, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
3 CEA, DAM, DIF, F-91297 Arpajon Cedex, France
4 Université Côte d’Azur, CNRS, Institut de Physique de Nice, Nice, France
5 Institute of Physical Chemistry Polish Academy of Sciences, Warsaw, Poland
* Corresponding author: Antonio.Picozzi@u-bourgogne.fr
Published online: 18 October 2023
Nonlinear random waves exhibit a phenomenon of irreversible thermalization, in analogy with the thermalization of a classical gas system. This irreversible process of thermalization to the Rayleigh-Jeans equilibrium distribution has been recently observed experimentally in multimode optical fibers. Here we discuss a recent progress along two different directions. Firstly, we report the observation of thermalization to negative temperature equilibrium states, in which high-order fiber modes are more populated than low-order modes. Secondly, we analyze the impact of disorder inherent to light propagation in multimode fibers. We identify an unexpected regime in which strong random coupling among non-degenerate modes leads to a nonequilibrium process of Rayleigh-Jeans thermalization.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
