Large-area tungsten disulfide for ultrafast photonics

Abstract

Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have attracted significant interest in various optoelectronic applications due to their excellent nonlinear optical properties. One of the most important applications of TMDs is to be employed as an extraordinary optical modulation material (e.g., the saturable absorber (SA)) in ultrafast photonics. The main challenge arises while embedding TMDs into fiber laser systems to generate ultrafast pulse trains and thus constraints their practical applications. Herein, few-layered WS with a large-area was directly transferred on the facet of the pigtail and acted as a SA for erbium-doped fiber laser (EDFL) systems. In our study, WS SA exhibited remarkable nonlinear optical properties (e.g., modulation depth of 15.1% and saturable intensity of 157.6 MW cm) and was used for ultrafast pulse generation. The soliton pulses with remarkable performances (e.g., ultrashort pulse duration of 1.49 ps, high stability of 71.8 dB, and large pulse average output power of 62.5 mW) could be obtained in a telecommunication band. To the best of our knowledge, the average output power of the mode-locked pulse trains is the highest by employing TMD materials in fiber laser systems. These results indicate that atomically large-area WS could be used as excellent optical modulation materials in ultrafast photonics.

2D Layered Materials: Synthesis, Nonlinear Optical Properties, and Device Applications

“…These efforts have greatly promoted the development of few‐layer MoS 2 in mode‐locked lasers and achieved a lot of important results . Similar to MoS 2 , layered WS 2 also has a direct bandgap and exhibits excellent nonlinear optical properties . For example, the researchers demonstrated the soliton mode‐locked fiber lasers using WS 2 nanosheets, which were prepared by the liquid phase exfoliation and pulsed laser deposition method, respectively, as shown in Figure a–f.…”

Recent Advances of 2D Materials in Nonlinear Photonics and Fiber Lasers

“…However, the difference in PE is relatively large. Except for the lasers of up to 128.3 nJ implemented by the team of Yan et al,252 the PE of another MLFLs varied from nJ to pJ.…”

Broadband Nonlinear Photoresponse of 2D TiS2 for Ultrashort Pulse Generation and All‐Optical Thresholding Devices

“…In recent years, 2D TMDs with graphene‐like structures have also been the subject of intense investigations. Optoelectronic devices built on few‐layer TMDs exhibit outstanding performances owing to their layer structure and abundance of transition metal d electrons . TiS 2 is a typical TMD with excellent electrical conductivity and stability, which has been previously developed for battery electrodes, stamp‐transferrable electrodes, photothermal therapy, and photodetectors .…”