Optimal sparse networks for synchronization of semiconductor lasers

TL;DR

This paper demonstrates that optimally designed sparse coupling networks can achieve near-complete synchronization of semiconductor lasers, often outperforming fully coupled networks by strategically placing weights on pairs with large frequency differences.

Contribution

It introduces the concept of optimal sparse network configurations for laser synchronization and explains their effectiveness through a thermodynamic potential theory.

Findings

Sparse networks can outperform fully coupled networks in synchronization.

Strategic weighting on pairs with large frequency differences enhances synchronization.

Optimal sparse configurations are scalable and cost-effective.

Abstract

The inevitable random frequency differences among semiconductor lasers present an obstacle to achieving their collective coherence, but previous worked showed that fully (all-to-all) coupled networks can still be synchronized even in the weakly coupling regime. An outstanding question is whether sparsely coupled network structures exist that lead to strong synchronization. This paper gives an affirmative answer: optimal sparse coupling configurations can be found which enables near-complete synchronization. Quite surprisingly, with respect to synchronization, certain sparse networks can outperform fully coupled networks, when the weights of coupling are placed dominantly on the laser pairs with large frequency differences. The counterintuitive phenomenon can be explained by a thermodynamic potential theory that maps the time-delay-induced phase dynamics to an energy landscape. These findings suggest a scalable and cost-effective approach to achieving robust, steady-state synchronization of semiconductor lasers in the presence of disorder and noise.