https://doi.org/10.1351/goldbook.09197
Measurement method for the thickness of transparent surface films and layers and for the refractive index of a reflecting material.
Notes:
- Radiation that is linearly polarized oblique to the surface becomes elliptically polarized after reflection at non-normal incidence. The ellipticity is obtained from measurements of the intensity and polarization of the incident and the reflected radiation.
- Ellipsometry may utilise monochromatic light, while spectroscopic ellipsometry employs a range of frequencies.