通过双色激光场和低频电场合成获得孤立40阿秒脉冲

本文提出了一个在双色激光场上叠加低频电场来拓宽高次谐波谱平台区域,从而获得孤立40阿秒脉冲的方案.计算中,我们针对氦原子数值求解了一维含时薛定谔方程,并结合电子的经典回碰动能随时间分布图以及时频分析图,分析了低频电场对高次谐波谱产生过程的影响.计算结果表明,该方案可以有效的拓宽谐波谱的平台区域.通过叠加适当阶数的谐波谱,我们得到了孤立40阿秒脉冲.

An isolated 40 attosecond pulse generated by using

In this paper, we propose a method to expand the plateau of high-order harmonic spectrum by using the combination of a two-color laser pulse and a low-frequency field, and an isolated 40as pulse is obtained finally. We numerically solve time-dependent Schrödinger equation for the one-dimensional model of helium atom in an intense laser field, analyzing the influence of low-frequency field on high-order harmonic generation (HHG) with classical returning kinetic-energy map and time-frequency distribution. Results show thatnot only is the plateau of harmonic spectrum extended efficiently, but also can the 40as extremely short pulse be obtained by superposing a properly selected range of the harmonic spectrum region.