Field-Free Molecular Orientation with a Few Half-Cycle Pulses in the Terahertz Region

A theoretical scenario used for achieving efficient field-free molecular orientation with a few half-cycle pulses (HCPs) is proposed, with the LiH molecule as an example. Compared with a single HCP, three HCPs can excite more rovibrational transitions and enhance the degree of molecular orientation. By optimizing the laser parameters, a maximum value of 0.798 for the degree of molecular orientation is obtained.