Broadband Nonlinear Photonics in Few‐Layer Borophene

Abstract

In this paper, 2D borophene is synthesized through a liquid‐phase exfoliation. The morphology and structure of as‐prepared borophene are systemically analyzed, and the Z‐scan is used to measure the nonlinear optical properties. It is found that the saturable absorber (SA) properties of borophene make it serve as an excellent broadband optical switch, which is strongly used for mode‐locking in near‐ and mid‐infrared laser systems. Ultrastable pulses with durations as short as 792 and 693 fs are successfully delivered at the central wavelengths of 1063 and 1560 nm, respectively. Furthermore, stable pulses at a wavelength of 1878 nm are demonstrated from a thulium mode‐locked fiber laser based on the same borophene SA. This research reveals a significant potential for borophene used in lasers helping extending the frontiers of photonic technologies.

Recent Progress on Two-Dimensional Materials

“…Borophene is a promising nonlinear optical material with both nonmetallic and metallic properties which can facilitate polymorphism in low-dimensional structures. Ma et al 492 studied intriguing nonlinear properties of borophene prepared with the liquid-phase exfoliation method and their potential applications. The broadband nonlinear photonic characteristics of borophene are shown in the Fig.…”

2D boron nanosheet architectonics: opening new territories by smart functionalization

“…First, the yield, thickness, solubility and stability could be effectively adjusted by these functional groups. 38,91 Second, functional groups can alter the adsorption energy towards different species in the reaction, and therefore change the reaction kinetics. 90 Note that different functional groups could be introduced simultaneously using one single solvent, which consequently bring about multiple variables impacting the properties.…”

“…On the other hand, free-standing boron nanosheets have been effectively prepared via top-down approaches, mainly by liquid phase exfoliation (LPE) of bulk boron or MgB 2 . [36][37][38][39] During this process, various functional groups in liquid media are simultaneously attached to the surface of boron sheets. 37,39 These functional groups can stabilize the exfoliated boron nanosheets and simultaneously tune their properties, therefore leading to versatile applications.…”

Exploring the emerging applications of the advanced 2-dimensional material borophene with its unique properties

“…The features of borophene with its capability of absorption, hybridization, optical modulation 221 along with atomic layer thickness 222 and excellent optical nonlinearity 223 play an important role in photonic and electronic devices. It was reported that in a 2D borophene synthesized via liquid -phase exfoliation, when its nonlinear optical properties were measured through Z-scan, the observed saturable absorber (SA) properties indicated that it could serve as an excellent broadband optical switch that could be used for ultrafast mode-locking in mid-infrared and near infrared laser systems.…”