On the new potentials of ellipsometry arising from the null optical circuit. Ellipsometry of real surface structures. 10. Null ellipsometry methods for measuring polarization angles. Problem of accuracy improvement

In connection with the problem of ellipsometry accuracy improvement, the paper presents successive derivation and analysis of ellipsometry zonal relations for a general case of arbitrary orientation of the compensator "fast" axis with respect to the plane of incidence. Those zonal relations define polarization angles Ψ and Δ (by the positions of optical elements quenching) in each of 4 measurement zones. The technique of averaging the polarization angles (zonal relations) over the pairs of measuring zones has been generalized. The paper demonstrates that such a procedure makes weaker the explicit dependence on the compensator parameter only in a sufficiently narrow interval of the compensator "fast" axis angular positions. The problem of ellipsometric measurement accuracy improvement in the Ψ and Δ ranges where the intensity minimum of light beam at the analyzer output is weakly defined (by one or two quenching parameters) is discussed. Weight of evidence suggests that this minimum can be considerably intensified by fitting the "fast" axis position. The problem of ellipsometry measurement accuracy improvement will be considered in details in the next paper.