Molecular field-free alignment driven by femtosecond laser field

The field-free alignment behaviors of some molecules driven by the femtosecond laser pulses are theoretically investigated. We detailedly discuss the temporal evolution of the molecular rotational wave-packet under different laser intensities, different laser pulse durations and different molecular rotational temperatures. The results show that the degree of the molecular alignment depends not only on the laser intensity and the laser pulse duration, but also on the molecular rotational temperature. Finally, we demonstrate the feasible approaches to enhance the molecular alignment degree for practical application.