2D MoTe2 film as a saturable absorber for a wavelength-tunable ultrafast fiber laser

We have demonstrated the realization of wavelength-tunable pulse outputs in a mode-locked fiber laser by utilizing 2D ${{\rm MoTe}_2}$MoTe2 film as the saturable absorber (SA). The SA is synthesized by coating 2D ${{\rm MoTe}_2}$MoTe2 film on the pinhole of the fiber pigtail and it can work stably at the mode-locking state for several weeks, indicating that the 2D ${{\rm MoTe}_2}$MoTe2 film is a suitable SA for ultrafast optics. The ${{\rm MoTe}_2}$MoTe2 film mode-locked fiber laser can operate well at a wide spectral band, and the central wavelength of pulses is tunable in the range from 1530 to 1560 nm, which is attributed to the polarization-sensitive feature of the proposed SA. Our new SA will benefit high-power pulsed lasers, materials processing, and frequency comb spectroscopy.