标题： 脉冲内冲击过程在密气飞秒激光丝形成中的作用 显示英文标题

标题： Intrapulse Impact Processes in Dense-Gas Femtosecond Laser Filamentation

摘要： 能量获得和在强超短激光脉冲作用下的密集气体中的重新分布过程被理论研究，针对高压氩气的情况。 通过强场电离释放的电子在振荡激光场的作用下与中性邻近原子碰撞，从而通过短程逆轫致辐射相互作用在产生的电子气体中实现能量获得。 这些碰撞还会导致原子的激发和碰撞电离，从而减少电子气体的能量。 开发了一个描述这些竞争过程的动力学模型，该模型预测在激光脉冲结束时激发原子会超过电离原子。 在高压气体中脉冲期间产生大量激发原子与最近由Gao等人发现的脉冲尾迹中的延迟电离动力学一致。 [1] 这种能量重新分布机制提供了一种有效管理密集气体与强激光脉冲相互作用时的激发与电离模式的方法，从而为这些环境中的诊断和控制开辟了新途径。 显示英文摘要

摘要： The processes of energy gain and redistribution in a dense gas subject to an intense ultrashort laser pulse are investigated theoretically for the case of high-pressure argon. The electrons released via strong-field ionization and driven by oscillating laser field collide with neutral neighbor atoms, thus effecting the energy gain in the emerging electron gas via a short-range inverse Bremsstrahlung interaction. These collisions also cause excitation and impact ionization of the atoms thus reducing the electron-gas energy. A kinetic model of these competing processes is developed which predicts the prevalence of excited atoms over ionized atoms by the end of the laser pulse. The creation of a significant number of excited atoms during the pulse in high-pressure gases is consistent with the delayed ionization dynamics in the pulse wake, recently discovered by Gao et al.[1] This energy redistribution mechanism offers an approach to manage effectively the excitation vs. ionization patterns in dense gases interacting with intense laser pulses and thus opens new avenues for diagnostics and control in these settings.