Linear polar molecule in a two-color cw laser field: A symmetry analysis

A theoretical study of the rotational dynamics of a linear polar molecule in a two-color nonresonant cw laser field is presented. By systematically considering the interactions of this field with the electric dipole moment, polarizability, and hyperpolarizability of the molecule, the implications that the symmetries of the Hamiltonian have on the rotational dynamics are explored in a regime where the time-average approximation does not hold. It is shown that the alignment and orientation satisfy certain symmetries as functions of the phases and field strengths, and that they can be expressed as analytic functions in terms of these main parameters of the two-color laser field.