Control of molecular-field-free orientation steered by asymmetric phase-jump laser pulses

Abstract

• The molecular orientation with phase-jump laser pulse is investigated by time-dependent quantum wave packet method. • The asymmetry of laser pulse has a significant influence on the orientation. • The molecular orientation is effected by the laser pulse parameters. A theoretical scheme used for manipulating the orientation of LiH molecules with phase-jump laser pulse is proposed. The time-dependent quantum wave packet method is used to numerically compute the wave-function of molecules by including both vibrational and rotational degrees of the freedom. The effect of asymmetric phase jump pulses on molecular orientation can be well understood by a train of HCPs kicking the molecule. The effective orientation of molecules can be achieved by phase-jump laser pulse. The maximal orientation degree, 0.757, and the longest orientation duration, 0.365 ps, are given by optimizing the parameters of phase-jump laser pulse. The molecular orientation is influenced significantly by phase and phase-jump time. Also the molecular orientation is dependent on pulse frequency, peak intensity and system temperature.