H_2~+分子双H核对高次谐波辐射的贡献

理论研究了H_2~+分子双H核对高次谐波辐射的贡献.结果表明:在少周期激光场下,由于激光场的反对称性,负向H核辐射谐波强度高于正向H核.随着激光脉宽增大,激光波形趋于对称,因此导致双H核辐射谐波的反对称结构减小.谐波辐射的时频分析图显示,当激光场为正向时(E(t)0.0),负向H核辐射谐波强度高于正向H核;当激光场反向时(E(t)0.0),正向H核辐射谐波强度高于负向H核.最后,通过分析含时电子波包及H_2~+的缀饰态给出了电子在双H核之间转移的原因.

Contributions of two-H nuclei in H2+ to high-order harmonic generation

Contributions of two-H nuclei in H2+ to high-order harmonic generation have been theoretically investigated. Result shows that in the few-cycle laser pulse, due to the asymmetry of the laser pulse, the contribution from the negative-H to the harmonic generation is higher than that from the positive-H. With the increase of the pulse duration, the profile of the laser pulse tends to symmetry, and thus leads to the decrease of the asymmetric harmonic distribution from two-H nuclei. Time-frequency analyses of the harmonic spectra show that when the laser field is larger than zero (E(t) > 0.0), the harmonic emission from the negative-H is higher than that from the positive-H; while when the laser field changes its direction (E(t) < 0.0), the harmonic emission from the positive-H is higher than that from the negative-H. Finally, through analyzing the time-dependent wave function and the dressed energies of H2+, we show the reason behind the electron motion/transfer between the two-H nuclei.