Controlling field-free molecular orientation with combined circularly and linearly polarized resonant pulses at low rotational temperatures

We calculated the field-free orientation of linear molecules irradiated by combined circularly and linearly polarized resonant pulses at finite rotational temperatures. We show that operating with a series of circularly polarized pulses, aided by a linearly polarized pulse, all in resonance with molecular rotational transitions, one can prepare a rotational wave-packet populating mainly on a few lowest rotational eigenstates whose magnetic quantum numbers M = 0. Starting from this wave-packet and employing a particular series of linearly polarized pulses, the degree of orientation can be remarkably enhanced and well controlled.