Temporal cavity soliton interaction in passively mode-locked semiconductor lasers

Abstract

Weak interaction due to gain saturation and recovery of temporal cavity solitons in a delay differential model of a long cavity semiconductor laser is studied numerically and analytically using an asymptotic approach. It is shown that apart from usual soliton repulsion leading to a harmonic mode-locking regime a soliton attraction is also possible in a laser with nonzero linewidth enhancement factor. It is shown numerically that the attraction can lead either to a soliton merging or to a pulse bound state formation.