Ti3C2Tx as Saturable Absorber for Highly Stable All Fiber Er-Doped Q-Switched Laser

We report on a Q-switched Er-doped all-fiber laser based on a solution-processed Ti₃C₂T_xsaturable absorber (SA). Ti₃C₂T_x is transferred to the fiber core region by optical deposition process through thermal effect. The Ti₃C₂T_x SA is clamped between two optical fiber connectors, which is flexible to integrate into the laser oscillator. The modulation depth and saturation incident fluence are measured to be ~3% and <inline-formula> <tex-math notation="LaTeX">$\sim 53.31~\mu \text{J}$ </tex-math></inline-formula>/cm² at 1550 nm wavelength region, respectively. At a threshold pump power of 190mW, we get self-started stable Q-switched operation with single-pulse energy of 22.17 nJ and pulse duration of <inline-formula> <tex-math notation="LaTeX">$\sim 7.07~\mu \text{s}$ </tex-math></inline-formula>. With the pump power varing from 190 to 280 mW, the repetition frequency (RF) changes from 52.8 kHz to 62.79 kHz. The maximum average output power is 2.14 mW, which corresponds to the single-pulse energy of 34.03 nJ. The short-term stability is obtained by measuring the RF and temporal sequences of output pulse for 12 hours. Moreover, the long-term stability is demonstrated by measuring the output power and repetition rate for one week, showing the highly stable operation of the Ti₃C₂T_x fiber laser, for the first time as far as we know.