H_2^+分子双H核对高次谐波辐射的贡献

Contributions of two-H nuclei in H_2^+ to high-order harmonic generation

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 H+2 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 H+2,we show the reason behind the electron motion/transfer between the two-H nuclei.