Complete determination of the state multipoles of rotationally resolved polarized fluorescence using a single experimental geometry

When laser radiation is used to prepare single rovibronic levels in molecules, the excited state Mj distribution is invariably polarized. In many such experiments the polarization of the excited state is ignored, which is an inadequate basis for accurate work as much valuable detail is lost. A better approach is a completely polarization resolved experiment in which the preparation, dynamics, and detection of the excited state polarization components (the state multipoles JJρKQ) are fully described. A treatment of polarized excitation in terms of the state multipoles JJρKQ is presented and consideration of excited state symmetry indicates that a common experimental geometry for linearly and circularly polarized excitation is feasible. A complete determination of the state multipoles (K=0,1,2) is shown to be possible within a single experimental geometry. It is shown that neglect of polarization phenomena can lead to ambiguities in the interpretation of some experiments.