We propose a scenario used for controlling molecular orientation with an infrared laser pulse and a delayed half-cycle pulse, with LiH molecules as an example. The infrared laser pulse excites the molecules in a thermally initial state to a specific rovibrational state, and the half-cycle pulse orients the molecules by rotational excitation. Numerical calculation shows that an efficient field-free time-dependent orientation can be realized even at room temperatures. The feasibility has been analyzed for LiH molecules under present experimental conditions.

• Received 20 May 2008

DOI:https://doi.org/10.1103/PhysRevA.78.055401