Modeling of Mueller matrix response from diffracting structures

Abstract

Mueller matrix ellipsometry becomes frequently used technique to characterize thin films, multilayers, nanostructures, and also more complex diffracting surfaces. Polarimetric study of new-generation solar cells with textured surfaces requires development of new modeling methods including phenomena as depolarization or s-p mode conversion. One of the effective modeling methods is calculation of the diffracted far field using diffraction integrals. This paper proposes a method to model ellipsometric and polarimetric response from an arbitrary diffracting element. We approximate the structure with the locally smooth piecewise surface with small surface curvature. The model neglects shadowing effect. The model is based on calculation of the complex amplitudes using the Fresnel-Kirchhoff diffraction integral of electromagnetic field near the surface. The surface can consist of arbitrary materials described by the complex refractive index or an arbitrary multilayer structure. The theory is demonstrated on reflection from a silicon substrate with silicon oxide layer in the form of the triangle with curved surface near edges.