Nonlinear optical properties and ultrafast photonics of 2D BP/Ti3C2 heterostructures

Heterostructures comprising two-dimensional (2D) materials have attracted increasing attention in recent years due to their unique properties. Here, a 2D black phosphorous (BP)/MXene (Ti3C2) heterostructure is prepared by stacking BP and Ti3C2 using van der Waals forces. Ultraviolet-visible absorption spectra proved the excellent stability of the heterostructure in water and air. In addition, strong nonlinear properties (high modulation depth with small saturation intensity) are demonstrated through Z-scan measurements, indicating that the BP/Ti3C2 heterostructure has excellent potential as an optical switch. To illustrate the applicability of the BP/Ti3C2 heterostructure ultrafast photonics, its performance as a saturable absorber in an Er-doped mode-locked fiber laser is demonstrated, resulting in a 735 fs pulse duration at a center wavelength of 1559.8 nm. Furthermore, harmonic mode-locking was also achieved by increasing the pump power, yielding a peak repetition rate of 588 MHz. These results reveal that 2D BP/Ti3C2 heterostructures have significant potential application in ultrafast photonics.

Automated summary

In this study, a 2D black phosphorous (BP)/MXene (Ti3C2) heterostructure was successfully prepared by stacking BP and Ti3C2 using van der Waals forces, demonstrating its excellent stability in water and air, as well as its potential as an optical switch. Nonlinear properties were also shown through Z-scan measurements, indicating high modulation depth and small saturation intensity. The performance of the BP/Ti3C2 heterostructure as a saturable absorber in an Er-doped mode-locked fiber laser was demonstrated, achieving a 735 fs pulse duration at a center wavelength of 1559.8 nm, along with harmonic mode-locking at a peak repetition rate of 588 MHz. These results suggest significant potential applications of 2D BP/Ti3C2 heterostructures in ultrafast photonics.