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

Abstract

2D titanium disulfide (TiS2) is recently found to have strong light absorption properties from visible to infrared (IR) region. This feature is highly attractive for applications in nonlinear photonics; however, the mechanism of broadband light–matter interaction is yet to be determined and nonlinear photonic devices are not developed. Here, for the first time, the experimental evidence supporting the mechanism of the broadband nonlinear photoresponse in ultrathin TiS2 nanosheets ranging from 400 nm to 1390 nm is reported through laser Z‐scan measurements. High‐performance nonlinear photonic devices operating in the telecommunication band are also demonstrated. A novel saturable absorber (SA) device is successfully fabricated based on a 2D TiS2‐decorated fiber, which exhibits outstanding ultrashort pulse generation performance with pulse duration of ≈1.04 ps centered at 1569.5 nm. Furthermore, as a stable all‐optical thresholding component, the device can effectively attenuate noise and boost the signal‐to‐noise ratio of the pulse from 1.90 to 10.68 dB. The findings indicate that TiS2‐based SA devices can be developed into excellent highly nonlinear photonic devices, which may advance the development of TiS2‐based optical communication technologies in the future.

2D Group IVB Transition Metal Dichalcogenides

“…Although TMDs such as MoS 2 , WS 2 , and ReS 2 exhibit great performance in the field of photodetectors, more in‐depth explorations on the optoelectronic applications of TMD family are still necessary . 2D Group IVB TMDs as great potential materials for photodetection applications have demonstrated some excellent photodetection properties, such as an extremely high responsivity, external quantum efficiency, and fast photoresponse.…”

Titanium Disulfide Based Saturable Absorber for Generating Passively Mode-Locked and Q-Switched Ultra-Fast Fiber Lasers

“…Recently, TiS 2 was reported as a superior nonlinear optical limiting material [ 47 ]. Additionally, TiS 2 used as SAs for generating pulsed laser operations have also been investigated preliminarily [ 44 , 48 , 49 ]. The light from 1530 nm to 1565 nm is a conventional band (C-band) that represents the regular waveband.…”

Nonlinear photoresponse of metallic graphene-like VSe2 ultrathin nanosheets for pulse laser generation

“…Owing to its metallic property and high electrical conductivity (1000 Sm −1 ) [26,27], VSe 2 has been extensively investigated as an anode material for practical energy storage, such as potassium-ion and lithium-ion batteries [28][29][30], but has never been applied in the field of pulse fiber lasers. Compared to several other broadband saturable absorbers (SAs), such as MXene [31], PtTe 2 [32], and TiS 2 [33], VSe 2 possesses many advantages, including that the zero band gap makes VSe 2 have universal optical response, relatively large layer spacing of 6.1Å [25,34] and weak van der Waals interactions render it easy to be exfoliated from bulk crystals. It is expected that VSe 2 could be a promising broadband SA applied in pulsed laser field with these merits.…”