The angle-of-incidence dependence of the differential reflection phase shift Δ between p and s polarizations is considered a function of the real and imaginary parts of the relative complex dielectric function ε of an interface in the domain of fractional optical constants, i.e., under conditions of internal reflection. The constraint on complex ε such that oscillatory and monotonic angular responses are obtained is determined. A sensitive and stable technique, which is based on attenuated internal reflection ellipsometry between the Brewster angle and the critical angle, is proposed for measuring small induced absorption (εi∼10−5) in the medium of refraction.
Journal of the Optical Society of America A
R. M. A. Azzam, "Differential reflection phase shift under conditions of attenuated internal reflection," J. Opt. Soc. Am. A 16, 1700-1702 (1999)