Ultrashort pulse generation hinges on the careful management of dispersion. Traditionally, this has exclusively involved second-order dispersion, with higher-order dispersion treated as a nuisance to be minimized. Here, we show that this higher-order dispersion can be strategically leveraged to access an uncharted regime of ultrafast laser operation. In particular, our mode-locked laser—with an intracavity spectral pulse shaper—emits pure-quartic soliton pulses that arise from the interaction of fourth-order dispersion and the Kerr nonlinearity. Phase-resolved measurements demonstrate that their pulse energy scales with the third power of the inverse pulse duration. This implies a strong increase in the energy of short pure-quartic solitons compared with conventional solitons, for which the energy scales as the inverse of the pulse duration. These results not only demonstrate a novel approach to ultrafast lasers, but more fundamentally, they clarify the use of higher-order dispersion for optical pulse control, enabling innovations in nonlinear optics and its applications.

超短脉冲的产生取决于对色散的仔细管理。传统上，这仅涉及二阶色散，而将高阶色散视为要最小化的麻烦。在这里，我们表明可以从策略上利用这种高阶色散来访问超快激光操作的未知领域。特别是，我们的锁模激光器（带有腔内光谱脉冲整形器）发出纯四次孤子脉冲，这些孤子脉冲是由四阶色散和Kerr非线性相互作用产生的。相位分辨测量表明，它们的脉冲能量与反向脉冲持续时间的三次方成正比。与常规孤子相比，这意味着短纯四分之一孤子的能量会大大增加，而常规孤子的能量按脉冲持续时间的倒数进行缩放。