Observation of decay of nonadiabatic molecular unidirectional rotation via time-resolved rotational Doppler spectroscopy

Abstract

In order to investigate the decay of nonadiabatic molecular unidirectional rotation (UDR) for nitrogen molecules, we measured the time-resolved rotational Doppler spectroscopy in first four revival periods after instantaneous excitation by a polarization shaped femtosecond laser. The results show that the rotational Doppler shifts decrease with increasing order of revival periods for full and half rotational revivals. Moreover, the maximum alignment of the molecular UDR at half rotational revivals was demonstrated to delay with revival periods increasing. This work is helpful to understand the kinetic processes of collisional decay for nonadiabatic molecular UDR, especially in the several revival periods after excitation.