Tungsten disulfide saturable absorbers for 67 fs mode-locked erbium-doped fiber lasers.

Zhiyi Wei,Hao Teng,Ming Lei,Shaobo Fang,Mengli Liu,Hainian Han,Lihui Pang,Wenjun Liu

doi:10.1364/oe.25.002950

Abstract

In this paper, we demonstrate 67 fs pulse emitting with tungsten disulfide (WS2) in mode-locked erbium-doped fiber (EDF) lasers. Using the pulsed laser deposition method, WS2 is deposited on the surface of the tapered fiber to form the evanescent field. The fiber-taper WS2 saturable absorber (SA) with the large modulation depth is fabricated to support the ultrashort pulse generation. The influences of the WS2 SA are analyzed through contrastive experiments on fiber lasers with or without the WS2 SA. The pulse duration is measured to be 67 fs, which is the shortest pulse duration obtained in the mode-locked fiber lasers with two dimensional (2D) material SAs. Compared to graphene, topological insulator, and other transition metal dichalcogenides (TMDs) SAs, results in this paper indicate that the fiber-taper WS2 SA with large modulation depth is a more promising photonic device in mode-locked fiber lasers with the wide spectrum and ultrashort pulse duration.

Highlights

Two dimensional (2D) material is a type of layered compounds, which are composed of the single layer or multiple layers of atoms [1]
Using the pulsed laser deposition (PLD) method, the WS2 is deposited on the fused zone of the tapered fiber
When the lights are propagated in the tapered fiber, they will leak out in the fused zone, and interact between the evanescent fields of the propagating lights

Summary

Introduction

Two dimensional (2D) material is a type of layered compounds, which are composed of the single layer or multiple layers of atoms [1] They have attracted much attention in basic and applied researches to the construction of photonic devices [2, 3]. Compared to other mode locking mechanism, the relatively high pump power has been needed for the mode-locked operation They have been influenced by environment conditions and usually have the relatively high modelocking threshold [7,8,9,10,11,12,13,14,15,16,17,18,19]. With the development of the material technology, 2D materials as broadband saturable absorption materials have been applied to the SAs preparation successfully, and 2D material SAs in fiber lasers have shown excellent performance [9,10,11,12,13,14,15,16,17,18,19]

Methods

Results

Conclusion