Laser excitation of molecules in thermal cells gives rise to an anisotropic distribution ofmstates and thus fluorescence from these states, and from levels populated by inelastic collisions, is polarized. Neglect of fluorescence polarization can give rise to misleading conclusions concerning population transfer in the excited state. Precise measurements of the transfer of population, orientation, and alignment, through polarization ratios, can provide an excellent means for testing the various fitting laws for rotationally inelastic transfer through modified lsquo;lsquo;suddenrsquo;rsquo; scaling laws. The justification for this is fourfold: rotational line strength factors and laser power fluctuations do not affect the degree of polarization; thirdly, the effect of multiple collisions is less significant on the inelastic polarization transfer than it is on the population transfer as measured in conventional total fluorescence intensity measurements; and fourthly, the leading parameters present in fitting laws cancel out, reducing the number of fitting parameters by one. Scaling laws appropriate to polarization measurements are derived and various fitting relations are tested against Li@B2/He and Liast;2/Ar rotationally inelastic polarization data.
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