Ellipsometry

Ellipsometry is an optical technique that uses polarised light to probe the dielectric properties of a sample (optical system). The common application of ellipsometry is the analysis of thin films. Through the analysis of the state of polarisation of the light that is reflected from the sample, ellipsometry yields information on the layers that are thinner than the wavelength of the light itself, down to a single atomic layer or less. Depending on what is already known about the sample, the technique can probe a range of properties including layer thickness, morphology, and chemical composition.