Multiple-angle-of-incidence ellipsometry

When plane-polarized light is reflected from the surface of a material at s ome oblique angle of incidence, the reflected light is, in general, ellipti cally polarized. The degree of ellipticity is determined by the optical par ameters (refractive index and absorption coefficient) of the reflecting med ium. Thus, using an ellipsometer to determine the degree of ellipticity ena bles a measurement of material parameters. In this review, we will concentr ate on ellipsometers in which the angle of incidence of light on the materi al is varied. The review will look at both the theoretical and practical pr oblems associated with this form of ellipsometry and will present some exam ples of its use from the literature.