Bimetallic solid solution MAX phase Ti₂NbAlC₂ as saturable absorber for passively Q-switched Er³⁺-doped fiber laser

In this paper, we demonstrated a stable Q-switched fiber laser operation with a central wavelength of 1531.43 nm using a bimetallic solid solution MAX phase Ti₂NbAlC₂ saturable absorber. The minimum pulse duration of 3.67 μs and the maximum repetition rate of 32.56 kHz were acquired at the pump power of 300 mW. Furthermore, the Q-switched pulse has a maximum output power of 1.08 mW and a maximum pulse energy of 33.14 nJ. Our results indicate that the Ti₂NbAlC₂ is a promising saturable absorber material. The bimetallic solid solution MAX phase materials may be developed as novel nonlinear photonic devices with outstanding performance.