Single layer equivalence of magneto-optic multilayers for normal incidence (I)

Abstract

The optical and magneto-optical properties of magnetic multilayer films are discussed in terms of a single equivalent layer. It is shown that, where two dissimilar absorbing layers, such as Co/Pt, are periodically repeated to produce a compositionally modulated structure, the resultant magnetic film may be described in terms of a single magneto-optically active layer, providing the individual layer thicknesses are very small compared with the wavelength of the probing radiation. This single layer equivalence applies at normal incidence only and simple expressions are obtained for the effective refractive index and magneto-optic parameter of the equivalent layer in terms of the basic optical and magneto-optical constants and thicknesses of the materials of the sub-layers.