Developing and utilizing laser manipulation techniques and coincidence measurement, the ionization of atoms/molecules in ultrafast intense laser fields with peak intensity up to 1016 W·cm−2 is investigatedto reveal important quantum effect in strong-fieldphysical processes. With aligned/oriented molecules through nonadiabatic excitation of rotational stateselected molecules enables us to give clear physicspictures for wavepacket dynamics and multi-orbitalcontribution in laser-matter interaction.

Neutral highlyingRydberg states are observed in the interaction ofdiatomic molecules with 50-fs laser fields both experimentallyand theoretically. By comparing the yieldof molecules with that of atoms, some quantum featuresare identified, helpful in understanding the underlying mechanism of this new strong field process.Combining the techniques for accurate orientation of molecules in free-space and pump-probetime-resolved coincident measurement of 3-dimension momenta of charged particles, we are conducting further studies toexplore various molecular multielectron effects in the dynamics both for ionizing electrons and rescattering electrons driven by ultra-short pulsed strong laserfields.