A New Thermodynamic Approach to Multimode Fibre Self-cleaning and Soliton Condensation

TL;DR

This paper introduces a thermodynamic framework for multimode optical fibers, explaining phenomena like self-cleaning and soliton condensation through a unified theory based on a weighted Bose-Einstein law.

Contribution

It presents a novel thermodynamic theory for multimode fiber optics, linking experimental regimes with a common thermalisation process using a new entropy-based approach.

Findings

Similar thermodynamic parameters in different propagation regimes

Unified explanation for self-cleaning and soliton condensation

Thermodynamic approach accurately models experimental results

Abstract

A new thermodynamic theory for optical multimode systems is proposed. Theory is based on a weighted Bose-Einstein law, and includes the state equation, the fundamental equation for the entropy and a metric to measure the accuracy of the thermodynamic approach. The theory is used to compare the experimental results of two propagation regimes in multimode fibres, specifically the self-cleaning in the normal chromatic dispersion region and the soliton condensation in the anomalous dispersion region. Surprising similarities are found in terms of thermodynamic parameters, suggesting a common basis for the thermalisation processes observed in the two propagation regimes.