Deposition of Ti2AlC MAX phase onto the side polished fiber as saturable absorber for soliton mode-locked fiber laser generation

The all-fiber Thulium/Holmium-doped mode-locked laser has been achieved at the threshold pump power of 149.2 mW using the passive technique. The titanium aluminum carbide (Ti2AlC) MAX Phase coated on the side polished fiber (SPF) was employed as a passive mode-locker to induce the laser generation. The fabricated Ti2AlC/SPF-based SA exhibits a strong nonlinear optical response with the normalized modulation depth, saturable intensity, and nonsaturable loss was calculated to be 2%, 1.7 MW/cm2, and 98%, respectively. The laser produced 1.38 ps pulses at the fundamental repetition rate of 12.05 MHz and operated at the wavelength of 1910 nm with full-width at a half-maximum spectral width of 3.1 nm. At the maximum pump power of 241 mW, the average output power, pulse energy, and peak power of 5 mW, 0.42 nJ, and 318 W were obtained. Furthermore, the mode-locking operation possesses good long-term stability with a signal-to-noise ratio of 70 dB. The obtained experimental results demonstrated the potential of Ti2AlC MAX Phase as an excellent candidate for short-pulse mode locker to realize long-term stable ultrashort pulsed laser at 1.9 μm wavelength region. The mid-infrared laser development is crucial for various applications, particularly in molecular spectroscopy and biomedical diagnostics.