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Our mission is to characterize the optical and structural properties of materials using polarized light. To do so, we provide experimental data consisting of ellipsometric - polarimetric measurements and we give advice and training on data mathematical analysis and physical interpretation.The service is available to researchers at Ecole polytechnique as well as to all those working for other public or private institutions and companies.
To illustrate our activities we will provide an introductory course to ellipsometry and polarimetry, some case studies and "success stories".
|Spectroscopic UV-VIS Ellipsometer|
|Spectroscopic VIS Polarimeter|
Ellipsometry is based on the measurement of the light polarization change upon reflection from a sample surface. It is used to characterize film thickness for single or multilayer stacks. Ellipsometry provides the 2x2 Jones Matrix that allow the determination of the refraction index (n), the absorption coefficient (k), crystallinity, film thickness and uniformity among others.
Polarimetry is based on the same principle that ellipsometry but is more general. It is ideal to measure complex surfaces such as anisotropic materials because it provides easy measurements of polarization degree, optical retardance, dichroism among others. Polarimetry provides 4x4 Mueller matrices that give enhanced information allowing precise metrology of patterned surfaces (diffraction gratings...).