电荷共振增强电离和离解电离在H~+_2谐波辐射中的贡献

理论研究了电荷共振增强电离和离解电离在H~+_2谐波辐射中的贡献.结果表明:在少周期激光场下,谐波辐射只由电荷共振增强电离贡献产生,谐波光谱呈规则的奇次谐波.在多周期激光场下,谐波辐射由电荷共振增强电离和离解电离共同贡献产生,但是电荷共振增强电离在谐波辐射中起主要作用.并且低阶谐波呈现偶次谐波.最后,通过分析含时核运动,电离几率以及谐波辐射时频分析图解释了少周期和多周期激光场驱动H~+_2辐射谐波的过程.

Contributions of charge-resonance-enhanced-ionization and dissociative ionization to high-order harmonic generation from H2+

Contributions of the charge-resonance-enhanced-ionization (CREI) and the dissociative ionization to the high-order harmonic generation (HHG) from H2+ have been theoretically investigated. It shows that in the presence of the few-cycle pulse, the HHG is only contributed by the CREI and the odd-order harmonics can be obtained. In the presence of the multi-cycle pulse, the harmonic emission comes from both the CREI and the dissociative ionization, but the CREI plays the main role in HHG. Moreover, both even-order and odd-order harmonics can be observed in the blow-threshold harmonics. Finally, the harmonic emission processes from H2+ driven by the few-cycle and multi-cycle pulses are explained in terms of the time-dependent nuclear motions, the ionization probabilities and the time-frequency analyses of the harmonic spectra.