摘要
数值研究了不对称分子He H2+在两束激光场形成的组合驱动场下发射高次谐波以及阿秒脉冲的特点.为了有效的展宽谐波的截止能量,基频场选择为5fs/800nm的啁啾激光场.计算结果表明,当啁啾参数和分子核间距分别选择为β=0.4和R=8.0a.u.时,不仅谐波波谱变得非常平滑而且其截止能量得到了有效的展宽.随后通过加入并且优化第二束控制激光场,谐波截止能量得到了进一步的展宽,形成了一个600e V的超平滑连续区.最后分别叠加280次到330次和330次到380次谐波可获得脉宽为78as的两个孤立阿秒X射线光源.
We theoretically investigate the generation of the high -order harmonic and the isolated attosecond X-ray sources when a model HeH 2＋molecule ion is exposed to a two -color field.In order to extend the harmon-ic cutoff energy, the fundamental field is chosen to the 5fs/800nm chirp pulse.The results show that when the chirp parameter and the internuclear distance are chosen to be β=0.4 and R=8.0a.u., respectively, not only the harmonic cutoff energy has been remarkably enhanced , but also the supercontinuum becomes very smooth . Further, by adding a subharmonic controlling pulse with the optimized conditions , a supercontinuum with a bandwidth of 600eV can be obtained.Finally, by respectively superposing harmonics from the 280th to the 330th orders and from the 330th to the 380th orders, two isolated X-ray pulses as short as 78 as can be generated .
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2015年第2期269-274,共6页
Journal of Atomic and Molecular Physics
基金
辽宁工业大学教师科研启动基金资助的课题(X201319)
关键词
高次谐波
阿秒脉冲
不对称分子
High-order harmonic generation
Attosecond pulse
Asymmetric molecule
