Self-Start Wide Tuning Mode-Locked Fiber Laser at 2µm Spectral Region

Introducing a wideband tunable mode-locked fiber laser operating in the spectral range from 1856 to 2000 nm, with a 3.5 MHz repetition rate and over 5 mW average power from the seed fiber laser. It utilizes 2 m Thulium-Holmium co-doped fiber (THF) as the gain medium, incorporating a semiconductor saturable absorber mirror (SESAM) for passive mode-locking. This laser system achieves exceptional wavelength tunability while maintaining a low repetition rate. The self-starting nature ensures stable operation, with an average pulsewidth of 1.5 ns. The low repetition rate makes it suitable for time-resolved measurements and nonlinear frequency conversion. The laser's wide wavelength tunability, narrow linewidth, and low repetition rate make it valuable for scientific and industrial applications, including spectroscopy, gas sensing, and ultrafast photonics.