MoTe2 Saturable Absorber With High Modulation Depth for Erbium-Doped Fiber Laser

Transition metal dichalcogenides have recently been considered the candidates for saturable absorption materials due to their advantages in both electronic and optoelectronic. Compared with MoS
₂
and WS
₂
, MoTe
₂
exhibits smaller bandgap. As a result, MoTe
₂
owns inherent advantages in the near-infrared applications. In this paper, the MoTe
₂
saturable absorber (SA) were prepared by the magnetron sputtering deposition method. Owing to the enhanced light-materials interaction between MoTe
₂
and evanescent field from the microfiber, the modulation depth of the MoTe
₂
SA was up to 26.97%. By assembling the MoTe
₂
SA into the erbium-doped fiber laser, the mode-locked fiber laser at 1.5 μm was demonstrated. The pulse duration of 111.9 fs was proved to be the shortest in the fiber lasers based on transition metal dichalcogenides. Moreover, the mode-locked fiber laser maintains the long-term stability. Our results suggest that the proposed MoTe
₂
SA is promising for the ultrashort pulse generation and stable system operation.