摘要
研究了氦离子在中红外组合激光场作用下的高次谐波辐射和孤立阿秒脉冲的产生.研究结果表明,当主脉冲强度相对低时,谐波截止在657阶次处,形成一个宽度为287eV的连续谱.当主脉冲强度相对高时,可使谐波截止拓展到1795阶次,连续谱加宽到834eV.在两种情况下,我们实现了长量子路径选取,并且产生转换效率较高的连续谱.特别是对于相对高的激光强度,叠加450～1590阶次内任意87eV的谐波都可以直接得到50as以内的单个脉冲.
We theoretically study high-order harmonic and isolated attosecond pulse generation from a model helion ion in the combination of the mid-infrared （mid-IR） laser and an extreme ultraviolet （xuv） pulse. It is shown that, for the low laser intensity, the harmonic cutoff is at about 657 th order, and the supercontinuum with a 287 eV bandwidth is formed. For the high laser intensity, the spectral cutoff is enlarged to 1795 th order, and the supercontinuum is broadened to 834 eV. In the two cases, both the long quantum path selection and the enhancement of the supercontinuum are achieved. Especially for the relatively high laser intensity, pure isolated sub-50 as pulses can be directly obtained by superposing an arbitrary 87 eV harmonics in the supercontinuum from 450 th to 1590 th order.
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2013年第3期421-426,共6页
Journal of Atomic and Molecular Physics
基金
宝鸡文理学院重点科研项目(ZK11135
ZK10122
ZK11061
ZK11060)
关键词
高次谐波辐射
孤立阿秒脉冲
组合场
high-order harmonic generation, isolated attosecond pulse, combined field
