Spontaneous synchronisation and exceptional points in breather complex

TL;DR

This paper experimentally demonstrates spontaneous synchronization and exceptional point-induced pulse generation in breather complexes within mode-locked fiber lasers, linking non-Hermitian physics to laser stability and ultrafast optics.

Contribution

It reveals a new pulse generation mechanism related to exceptional points and synchronization in breather complexes, advancing understanding of non-Hermitian effects in laser systems.

Findings

Synchronization occurs during breather complex formation.

Pulse generation is linked to exceptional points and subharmonic entrainment.

Laser stability is connected to breather synchronization.

Abstract

We experimentally demonstrate the spontaneous synchronization and the exceptional point (EP) induced pulse generation mechanism in the breather complex. The breathing frequency and phase are found to be synchronized during the formation of a 9-breather assembled complex in a mode-locked fiber laser. The breathers are formed at exactly the time point of the complex's breathing frequency leaving or entering the subharmonic entrainment. Such new pulse generation mechanism should be related to the non-Hermitian EPs or the time translation symmetry breaking. The investigations of destroying and rebuilding the mode-locking reveal the connection between the synchronization and laser stabilization. These findings may inspire a wide range of researches including ultrafast optics, micro-cavity combs, ocean breather behaviors, non-Hermitian optics, etc.