The polarization of sensitized fluorescence

By means of the selection rule Σ m J = constant along the axis of a collision between two atoms, it is shown that sensitized fluorescence should in some cases be partially polarized. The degree of polarization of the fluorescence of cadmium vapour sensitized by the presence of mercury vapour is calculated for certain states of polarization of the incident radiation. In the case studied experimentally the degree of polarization varies over a range of 2-5%. The theoretical value is 3/11, which is reduced in practice by various depolarizing effects. The possibility of transfer coherence between eigenstates from mercury to cadmium during a collision is considered.