Generation of Picosecond Pulses in Erbium-Doped Fiber Lasers Via Mode Locking Using V₄AlC₃ Thin Film

Short pulses are showing increasing importance in various industrial and scientific applications. Here, we exploit the saturable absorption of a ternary layered MAX-phase compound of Vanadium Aluminum carbide (V₄AlC₃) to produce mode-locked pulses in Erbium-doped fiber-laser (EDFL) cavity. The V₄AlC₃ composite thin film with a modulation depth of 24% is successfully obtained by embedding the commercial V₄AlC₃ powder into polyvinyl alcohol (PVA). It is integrated into an EDFL cavity, as a saturable absorber (SA), to generate a highly-stable mode-locked pulse, which operates at the 1559.8 nm wavelength. We successfully obtain the mode-locked pulse train with a fixed repetition rate of 1.8 MHz and a pulse width of 3.66 ps, as the pump power is set within a range from 73.1 to 108.1 mW. At the maximum pump power equal to 108.1 mW, the average output power, pulse energy, and peak power are 10.2 mW, 5.4 nJ, and 1.5 W, respectively. Overall, these results show the potential of V₄AlC₃ MAX-phase material to be used in ultrafast generation. The proposed approach is straightforward and can also be applied to operate in other wavelength regions.