Cr₂AlB₂/PbS heterostructure as saturable absorber for ultrashort pulse generation

Rapid progress has been realized in the nonlinear optical device applications of 2D materials. 2D materials are attractive due to their characteristics optical nonlinearities and distinctive light-matter interactions, which assure them promising nonlinear optical devices for ultrashort pulses generating. Cr₂AlB₂, a member of the new series of 2D materials known as MBenes, has been predicted to have potential saturable absorption properties. In this study, the saturable absorption properties of Cr₂AlB₂ and Cr₂AlB₂/PbS vdW heterostructure SAs are investigated. In comparison with Cr₂AlB₂, the Cr₂AlB₂/PbS vdW heterostructure exhibits better saturable absorption. The enhancements of nonlinear optical properties can be attributed to the carrier migration between heterostructure. The simulation results based on the Ginzburg-Landu equation are employed to predict the laser performances of Cr₂AlB₂ and Cr₂AlB₂/PbS heterostructure SA. By incorporating SAs in the cavity, highly stable conventional solitons were observed. Both simulation and experimental results demonstrate that Cr₂AlB₂/PbS vdW heterostructure has superior pulse performance compared to the Cr₂AlB₂ SA. These results demonstrate that Cr₂AlB₂/PbS vdW heterostructure processes better saturable absorption properties and serves as a promising SA in ultrashort pulse generation.