标题： 由二维正弦-戈登方程描述的超短光弹 显示英文标题

标题： Ultrashort light bullets described by the two-dimensional sine-Gordon equation

摘要： 通过应用二维模型的约化摄动技术，本研究提出了一种通用的二维正弦-戈登演化方程，用于描述在克尔介质中超出缓慢变化包络近似范围的飞秒时空光学孤子的传播。 直接数值模拟显示，与长波近似相反，不会发生坍缩，并且可以从适当选择的少周期输入时空波形中形成稳定的（2+1）维超短光子弹。 与二次非线性的情况不同，光子弹在空间和时间上都会振荡，因此不是稳态的块状物。 显示英文摘要

摘要： By using a reductive perturbation technique applied to a two-level model, this study puts forward a generic two-dimensional sine-Gordon evolution equation governing the propagation of femtosecond spatiotemporal optical solitons in Kerr media beyond the slowly varying envelope approximation. Direct numerical simulations show that, in contrast to the long-wave approximation, no collapse occurs, and that robust (2+1)-dimensional ultrashort light bullets may form from adequately chosen few-cycle input spatiotemporal wave forms. In contrast to the case of quadratic nonlinearity, the light bullets oscillate in both space and time and are therefore not steady-state lumps.