A Note on the Theories Underlying the Polarimetric Study of Very Thin Dielectric Surface Layers

Polarimetric study of very thin dielectric surface layers on dielectric substrates has been most frequently based on Drude's theory, or on Sissingh and Groosmuller's theory obtained by improving the approximation of Drude's calculation. These theories are derived by modifying the boundary conditions for Maxwell's equations. A quite different approach to this problem is possible, however, which is based on discussions concerning the interference of light inside the surface layer. It has been proved by several workers that Drude's theory is consistent with the interference theory. It is proved in this paper that Sissingh and Groosmuller's theory is also consistent with the interference theory. Some formulae derived in the process of proof are believed to be useful for further discussions in this field.