Über die bestimmung der optischen konstanten dünnster oberflächenschichten und das problem der schichtdicke

The Fresnel reflection coefficients of a phase boundary disturbed by values of the optical constants differing from the values in the adjacent phases (boundary phase) are derived. The derivation on the basis of Maxwells' theory uses integral boundary conditions. The deviations from the ideal reflection properties, caused by a boundary phase with uniaxial symmetry, are proportional to the difference of the dielectric constants (for the tangential component) and to the difference of the reciprocal values of the dielectric constants (for the normal component) to the value in the undisturbed case, integrated over the boundary phase. An optical thickness of the boundary phase can not be determined by means of ellipsometry or reflection spectroscopy.