Ti₃CN, as a typical hetero-MXene, has attracted tremendous attention for its unique properties. However, its ultrafast photonics applications are still rare. Here, the few-layer Ti₃CN MXene was successfully prepared by selective etching and molecular delamination technique. The nonlinear optical response of few-layer Ti₃CN MXene at 640 nm was studied using the open-aperture Z-scan technique. The as-prepared Ti₃CN MXene sample exhibited excellent nonlinear saturable absorption characteristics, resulting in the nonlinear absorption coefficient β of −4.05 × 10^-2 cm/GW, which was one order of magnitude larger than that of black phosphorus (BP) and molybdenum disulfide (MoS₂). For the optical modulation applications of few-layer Ti₃CN MXene, passively Q-switched (PQS) solid-state visible lasers based on Ti₃CN saturable absorber (SA) at 522 nm, 607 nm, 639 nm, and 721 nm were successfully realized. Furthermore, a Ti₃CN-based stable passively mode-locked Pr:YLF red laser was also successfully achieved with a pulse duration of 30 ps, and the corresponding repetition rate was 73.1 MHz. The optical modulation device based on few-layer Ti₃CN MXene shows good performance. Our work demonstrates that the tremendous prospects of the few-layer Ti₃CN MXene as a visible optical modulation device in ultrafast photonics applications.

Ti ₃ CN作为典型的异质MXene，以其独特的性能引起了极大的关注。然而，其超快光子学应用仍然很少见。在这里，通过选择性蚀刻和分子分层技术成功制备了少层 Ti _{3 CN MXene。}使用开孔Z扫描技术研究了少层 Ti ₃ CN MXene 在 640 nm 处的非线性光学响应。所制备的Ti ₃ CN MXene样品表现出优异的非线性可饱和吸收特性，非线性吸收系数β为-4.05×10 ^-2  cm/GW，比黑磷（BP）高一个数量级，二硫化钼（MoS ₂). 对于少层 Ti ₃ CN MXene 的光学调制应用，在 522 nm、607 nm、639 nm 和 721 nm 处，基于 Ti ₃ CN 可饱和吸收体（SA）的被动调Q（PQS）固态可见激光器成功实现。此外，还成功实现了基于 Ti ₃ CN 的稳定被动锁模 Pr:YLF 红色激光器，脉冲持续时间为 30 ps，相应的重复频率为 73.1 MHz。基于少层Ti ₃ CN MXene的光调制器件表现出良好的性能。我们的工作证明了少层 Ti ₃ CN MXene 作为可见光调制器件在超快光子学应用中的巨大前景。