The effects of generalized component imperfections, azimuth-angle errors, and errors of the normalized Fourier coefficients of the detected photoelectric current on the measured ratio of reflection coefficients ρ in rotating-analyzer ellipsometers (RAE) are determined. The problem is formulated in such a way that much of the earlier work done on error analysis for null ellipsometers (NE) can be adapted to RAE. The results are conveniently expressed in terms of coupling coefficients that determine the extent to which a given source of error couples to an error of the measured value of ρ. The optical properties of the compensator (if used) and of the surface can be simultaneously obtained from a set of two measurements using RAE, in a manner similar to two-zone measurements in NE. In addition, novel methods of obtaining and combining the results from two measurements are examined, with the objective of cancelling the effect of many of the systematic sources of errors. One such method employs two incident polarizations of the same ellipticity but with orthogonal azimuths, in which case the measured value of ρ is almost independent of the input optics. If the two incident polarizations are chosen, instead, to have equal but opposite ellipticity and azimuth, the effects of the polarizer imperfection, off-diagonal elements in the compensator, entrance-window, surface, and exit-window imperfection matrices, as well as polarizer and compensator azimuth-angle errors, all disappear upon such two-measurement averaging; the effects of analyzer imperfection or azimuth-angle error and errors of the normalized Fourier coefficients are only partially cancelled. Finally, use of RAE in generalized ellipsometry and its attendant problems are examined.
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