Multichannel molecular high-order harmonic generation from HeH2+ with the combination of a chirped laser and a unipolar pulse

作者：Zhang, Jun; Du, Hui; Liu, Hai-Feng; Guo, Jing; Liu, Xue-Shen^*

来源：Optics Communications, 2016, 366: 457-461.

DOI：10.1016/j.optcom.2015.12.044

• High-order harmonic generation
• Asymmetric molecule
• Chirped laser pulse
• A unipolar pulse

The high-order harmonics from the asymmetric molecule HeH2+ with the combination of a chirped laser and a unipolar pulse is investigated by solving non-Born-Oppenheimer approximation time-dependent Schrodinger equation. We illustrate the multichannel molecular high-order harmonic generation by using a chirped laser pulse with carrier envelope phase (CEP) phi = 0 plus a unipolar pulse, and a chirped laser pulse with CEP phi = pi 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.

• 出版日期2016-5-1
• 单位吉林大学