The source of errors in depolarization measurements using laser excitation and their dependence on monochromator, image magnification, and cell geometry is considered. Two common ways of measuring these ratios are considered, and the extent of the expected divergence errors in capillary cells is calculated for the 90° scattering geometry. It is shown that the ratio ρn determined by rotating the laser polarization from perpendicular to parallel to the scattering direction is subject to errors which limit its usefulness for highly polarized lines but is acceptable for depolarized lines. Use of an analyzer gives depolarization ratios ρs with the highest accuracy.
