A multiple soliton state erbium-doped fiber laser based on a MoS2/C saturable absorber

Abstract

Transition metal dihalide (TMD) heterojunction materials possess distinct advantages in the field of optoelectronics, which has resulted in their extensive research in recent years. In this work, MoS₂/C heterojunctions were synthesized using a hydrothermal method and deposited onto a tapered fiber with a diameter of 10.93 μm to form saturable absorbers (SAs) using photodeposition. The integration of MoS₂/C SA into an erbium-doped fiber laser (EDFL) enabled the realization of multiple stable and switchable mode-locking states under different dispersion conditions, including conventional solitons, bound-state solitons, and higher-order harmonic mode-locking. Among them, conventional solitons could be realised in the range of dispersion from −0.303 ps² to −1.18 ps², with the narrowest pulse width reaching up to 856 fs. Double-soliton bound states up to four-soliton bound states could be realized at a dispersion of −0.303 ps². At a dispersion value of −0.734 ps², a variety of higher-order harmonics could be achieved, with up to 88th harmonic mode-locking exhibiting a frequency of 499.7 MHz. These results demonstrate that MoS₂/C exhibits excellent nonlinear optical modulation properties and holds promise as a broadband nonlinear optical material.