Ellipsometry has a number of advantages compared to standard reflection intensity measurements:
* Ellipsometry measures at least two parameters at each wavelength of the spectrum. If generalized ellipsometry is applied up to 16 parameters can be measured at each wavelength.
* Ellipsometry measures an intensity ratio instead of pure intensities. Therefore, ellipsometry is less affected by intensity instabilities of the light source or atmospheric absorption.
* By using polarized light, normal ambient unpolarized stray light does not significantly influence the measurement, no dark box is necessary.
* No reference measurement is necessary.
Ellipsometry is especially superior to reflectivity measurements when studying anisotropic samples.