A simple analysis for the optimization of the normal polar magneto-optical Kerr effect in multilayer coatings containing a magnetic film

The Fresnel differential approach is used to derive a formula for the modulus of the normal polar Kerr coefficient for a multilayer system containing a single magnetic film. This particular function of the magneto-optical effect is chosen since it invariably appears in expressions for the signal-to-noise ratio associated with first order effects. The resulting formula determines how much superior optimized quadrilayers are than simpler bilayer structures, if at all; and also how the signal-to-noise ratio depends on the fundamental optical constants of the magnetic film.