Multichannel molecular high-order harmonic generation from HeH2+ with the combination of a chirped laser and a unipolar pulse
Multichannel molecular high-order harmonic generation from HeH2+ with the combination of a chirped laser and a unipolar pulse
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DOI：
10.1016/j.optcom.2015.12.044
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发表时间：
2016-05
影响因子：
2.4
通讯作者：
Jun Zhang;Hui-Ni Du;Hai-Feng Liu;Jing Guo;Xue-Shen Liu
中科院分区：
文献类型：
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作者：
Jun Zhang;Hui-Ni Du;Hai-Feng Liu;Jing Guo;Xue-Shen Liu
通过求解非born - oppenheimer近似时间依赖Schrödinger方程，研究了啁啾激光和单极脉冲联合作用下不对称分子heh2 +的高次谐波。本文分别用载波包络相位(CEP) φ= 0的啁啾激光脉冲加单极脉冲和CEP φ= π的啁啾激光脉冲减去单极脉冲说明了多通道分子高次谐波的产生。由于永久偶极矩的存在，在分子高次谐波发生（MHOHG）中，三步模型推广为四步模型。结果表明，在163 ~ 228阶范围内可观测到谱宽约65阶的超外连续谱，并具有双平台结构。此外，时频分析表明，啁啾激光与单极脉冲的组合可以抑制短量子轨迹，而抑制长量子轨迹。
The high-order harmonics from the asymmetric molecule HeH 2+ with the combination of a chirped laser and a unipolar pulse is investigated by solving non-Born–Oppenheimer approximation time-dependent Schrödinger equation. We illustrate the multichannel molecular high-order harmonic generation by using a chirped laser pulse with carrier envelope phase (CEP) φ= 0 plus a unipolar pulse, and a chirped laser pulse with CEP φ= π minus a unipolar pulse, respectively. Due to the presence of a permanent dipole moment, the three-step model is generalized to a four-step model in molecular high-order harmonic generation (MHOHG). The results show that an ultrabroad supercontinuum spectrum with a spectral width of about 65 orders from 163 orders to 228 orders and a two-plateau structure can be observed. Furthermore, the time–frequency analysis shows that the short quantum trajectory is left and the long one is suppressed with the combination of a chirped laser and a unipolar pulse.