Passive Q-switched fiber laser with MAX phase molybdenum titanium aluminum carbide film

In this work, we demonstrate a Q-switched erbium-doped fiber laser (EDFL), which is passively produced by using a saturable absorber (SA), which is fabricated by mechanical exfoliation of MAX phase molybdenum titanium aluminum carbide (Mo 2 Ti 2 AlC 3 ). Physical and optical properties of the SA are experimentally studied. The optical properties showed a good nonlinear absorption where the saturation intensity is 0.65 MW/cm 2 , with 40% of non-saturable absorption and 17% of modulation depth. The proposed EDFL is investigated using two output couplers (OCs) with split ratios of 50:50 and 80:20, respectively. For pumping power of 142 mW and coupling ratio of 50%, the proposed EDFL produced pulses with a pulse energy of 69.60 nJ, pulse width of 2.97 μs and repetition rate of 90.09 kHz. Besides, with coupling ratio of 20%, the EDFL can generate a pulse train with a pulse width of 1.91 μs, repetition rate of 77.64 kHz, and pulse energy of 89.52 nJ.