Perpendicular-incidence photometric ellipsometry (PIPE) of surfaces with arbitrary anisotropy

The authors describe the photoellipsometric measurement of an arbitrary normal-incidence-reflection Jones matrix of an anisotropic surface using an instrument with modulated polarizing/analyzing optics. Two modulation schemes are considered that employ (1) a synchronously rotating half-wave linear retarder; (2) a linear retarder of fixed azimuth whose relative retardation is periodically modulated as a linear saw-tooth function of time of pi (half-wave) amplitude. Reflection-matrix parameters are explicitly derived by Fourier analysis of the resulting periodic detected signal. Analysis of one signal is sufficient to determine a normalized diagonal or symmetric reflection matrix. Analysis of two signals, obtained in the presence and absence of a given Faraday rotation in front of the surface, permits the determination of any normalized reflection matrix of a surface with arbitrary anisotropy.