Generation of Bright-Dark soliton pairs in mode-locked fiber laser based on WSe2/MoSe2 heterojunction

In this study, the WSe2/MoSe2 heterojunction was fabricated by liquid-phase exfoliation (LPE) method with a modulation depth of 11.39 % and saturable intensity of 0.246 GW/cm2. The WSe2/MoSe2 heterojunction was used as a saturable absorber (SA) to achieve bright-dark soliton pairs modulation in Er-doped fiber laser (EDFL) successfully. Stable bright-dark soliton pairs, with a repetition frequency of 4.459 MHz, were successfully generated using a pump power of 218.8 mW. The central wavelengths were found to be at 1564.16 nm and 1564.98 nm with the peak-to-peak spacing of 0.82 nm. The single-pulse energy was determined to be 0.7 nJ. The experimental results demonstrate the exceptional nonlinear saturable absorption characteristics of the WSe2/ MoSe2 heterojunction. These findings offer valuable insights for future research on bright-dark soliton pairs utilizing this material.