Titanium Carbide MXene as a Mode Locker in Erbium-Doped Fiber Laser Cavity

We propose a MXene Ti₃C₂T_x thin-film and demonstrate as saturable absorber (SA) to generate mode-locked laser pulses. In constructing the SA, titanium carbide (Ti₃C₂T_x) powder obtained through a selective etching process is dispersed in polyvinyl alcohol (PVA) solution before the mixture is dried to form a thin film. A small piece of the film is placed between two fiber ferrules to form a SA device and added to an erbium-doped fiber laser (EDFL) cavity with a length of 106 m to produce mode-locked pulses. The mode-locked laser operates at 1561.2 nm with a repetition rate of 1.89 MHz and pulse width of 154 ns as the pump power is fixed within a range from 40.2 to 87.2 mW. At 87.2 mW pump power, the maximum average output power, pulse energy, and peak power were measured to be 11.85 mW, 6.24 nJ, and 40.7 mW respectively.