Mueller matrix spectroscopic ellipsometry: formulation and application

Abstract

Mueller matrix spectroscopic ellipsometry (MMSE) can be a powerful technique for the study and accurate determination of the dielectric function, optical properties and geometric characteristics of anisotropic materials and complex systems. In this work we present the formalism we developed in order to be able to calculate the sample Mueller matrix using phase-modulated ellipsometry. In order to test the formalism and check the information we can derive spectroscopically by a Mueller matrix, in comparison with standard spectroscopic ellipsometry, we proceeded to the study of an isotropic c-Si wafer and tested the ability of the formulation to calculate correctly its dielectric function using the M 33 and M 43 components in the energy region 1.5–6.5 eV. Also, we have used this formalism to obtain the MMSE spectra of a biaxially anisotropic SnSe bulk sample. Finally, we applied the Mueller matrix formalism for the study of biaxially stretched poly(ethylene terephthalate) (PET) film, as a representative complex anisotropic material. MMSE spectra were obtained for various angles of film's orientation, determined by the angle between the axis of preferential orientation of PET's macromolecules and the plane of incidence where the optical anisotropy of PET was verified. The interpretation of the MMSE spectra is found to provide more insights to the study of anisotropic materials.