Mo₂TiAlC₂ as a Saturable Absorber for a Passively Q-Switched Tm:YAlO₃ Laser

Owing to their remarkable characteristics, two-dimensional (2D) layered, MAX phase materials have garnered significant attention in the field of optoelectronics in recent years. Herein, a novel MAX phase ceramic material (Mo₂TiAlC₂) was prepared into a saturable absorber (SA) by the spin-coating method for passively Q-switching (PQS), and its nonlinear optical absorption properties were characterized with a Tm:YAlO₃ (Tm:YAP) nanosecond laser. The structure characteristics and composition analysis revealed that the Mo₂TiAlC₂ material exhibits a well-defined and stable structure, with a uniform thin film successfully obtained through spin coating. In this study of a PQS laser by employing a Mo₂TiAlC₂-based SA, an average output power of 292 mW was achieved when the absorbed pump power was approximately 4.59 W, corresponding to a central output wavelength of 1931.2 nm. Meanwhile, a stable pulse with a duration down to 242.9 ns was observed at a repetition frequency of 47.07 kHz, which is the narrowest pulse width recorded among PQS solid-state lasers using MAX phase materials as SAs. Our findings indicate that the Mo₂TiAlC₂ MAX phase ceramic material is an excellent modulator and has promising potential for ultrafast nonlinear photonic applications.