Thulium holmium-doped fiber laser mode-locked using Sb2Te3 saturable absorber coated arc-shaped fiber

In this study, the topological insulator (TI) antimony telluride (Sb2Te3) was used as a saturable absorber (SA) to obtain stable mode-locked pulses in a thulium holmium-doped fiber laser (THDFL). A liquid-phase exfoliation (LPE) approach was used to obtain the SA material without chemicals or surfactants. The SA device was prepared by drop-casting the material onto the arc-shaped fiber for integration into the 2.0 mu m laser cavity. The prepared device also exhibits nonlinear absorption properties with normalized modulation depth, saturation intensity, and non-saturable loss of 36.16 %, 0.046 MW/cm(2), and 63.84 %, respectively. Furthermore, stable mode-locked pulses were readily obtained at a pump power of 307.60 mW, where the center wavelength of the laser was recorded to be 1902.06 nm with a full width at half maximum of 2.88 nm. The pulses had a repetition rate of 10.88 MHz and pulse width of 1.32 ps with a signal-to-noise ratio (SNR) value of about 61.21 dB. The results show that Sb2Te3 SA demonstrated excellent performance and can be further explored for future photonics applications.

Automated summary

In this study, stable mode-locked pulses were achieved in a thulium holmium-doped fiber laser using Sb2Te3 as a saturable absorber. The SA material was obtained through liquid-phase exfoliation and integrated into the laser cavity. The experimental results demonstrate the excellent performance of Sb2Te3 SA and its potential for photonics applications.