摘要
Continuum wavepacket interference is investigated by numerically solving the time-dependent SchrSdinger equation for the interaction of hydrogen atoms with laser fields. The obtained wavepacket evolution indicates that, in the over-the-barrier ionization regime （1016 W/cm2）, the continuum-continuum （CC） interference of ionizing electrons becomes the main process in high- order harmonics generation （HHG）, compared with continuum-bound （CB） transition, as reported by Kohler et al. [Phys. Rev. Lett. 105（20）, 203902 （2010）]. We propose a two-color laser field scheme for controlling the quantum trajectories of ionizing electrons and for extending the CC harmonic energy. As a result, a high energy platform occurs in the HHG spectrum, which entirely originates from the CC harmonics, with a cutoff adjustable by the relative phase of the two-color fields. This provides further understanding of the dynamic feature of atoms and molecules in super intense laser fields and provides an opportunity to image the atomic or molecular potential.
Continuum wavepacket interference is investigated by numerically solving the time-dependent SchrSdinger equation for the interaction of hydrogen atoms with laser fields. The obtained wavepacket evolution indicates that, in the over-the-barrier ionization regime （1016 W/cm2）, the continuum-continuum （CC） interference of ionizing electrons becomes the main process in high- order harmonics generation （HHG）, compared with continuum-bound （CB） transition, as reported by Kohler et al. [Phys. Rev. Lett. 105（20）, 203902 （2010）]. We propose a two-color laser field scheme for controlling the quantum trajectories of ionizing electrons and for extending the CC harmonic energy. As a result, a high energy platform occurs in the HHG spectrum, which entirely originates from the CC harmonics, with a cutoff adjustable by the relative phase of the two-color fields. This provides further understanding of the dynamic feature of atoms and molecules in super intense laser fields and provides an opportunity to image the atomic or molecular potential.
基金
Acknowledgements This work was supported by the National Basic Research Program of China （973 Program） （Grant No. 2013CB922200） and the National Natural Science Foundation of China （Grants Nos. 1127403, 11274141, and 11534004）. We also acknowledge the High Performance Computing Center （HPCC） of Jilin University for supercomputer time.
