Manipulating molecular rotational wave packets with resonant terahertz pulses

We found the phase differences of the expansion coefficients in rotational wave packet are in linear relationships with the phases of corresponding pulses when gas-phase linear molecules are irradiated by pulses in resonant with their rotational transitions. Using these relationships, we can accurately control the wave packet by first determine the phases of the controlling pulses, and then optimize the durations (or amplitudes) of the pulses to demanded population. We also compared the phase relationships obtained from ground and other initial rotational eigenstates and analyzed the reason for lowered orientation degree in non-zero temperature conditions.