Field-free orientation dynamics of OCS molecule induced by utilizing two THz laser pulses

Field-free orientation of OCS molecule is studied theoretically by utilizing two THz laser pulses. The effects of the center frequency of THz laser pulses and the delay time between two THz laser pulses on molecular orientation are discussed. The molecular positive and negative orientation degrees can be changed to some extent by adjusting both the carrier envelope phases of two THz laser pulses. The maximal positive and negative orientation degrees obtained are ${⟨\cos \theta ⟩}_{\text{pmax}}=0.951$ and ${⟨\cos \theta ⟩}_{\text{nmax}}=-0.902$, respectively. Furthermore, the influence of the initial rotational temperature on molecular orientation is also investigated. (paper)