MXene saturable absorber for nanosecond pulse generation in a mid-infrared Ho,Pr:LLF bulk laser

In this paper, high quality few-layer MXene-Ti3C2Tx was fabricated by the LPE method and successfully applied as saturable absorber for a passively Q-switched (PQS) Ho,Pr:LLF laser operating at 2.95 µm. The maximum average output power was determined to be 105 mW with a slope efficiency of 5%. The shortest pulse width and the largest pulse repetition rate were determined to be 266.7 ns and 83.24 kHz, corresponding to the single pulse energy and pulse peak power of 1.26 µJ and 4.73 W, respectively. It is the first demonstration of MXenes applied in mid-infrared (MIR) PQS solid-state bulk lasers, to the best of our knowledge. The results not only verify the broadband nonlinear saturable absorption properties of MXenes, but also pave the way for exploring their applications in photonic devices.