Theory of Brillouin cross section for scattering from magnetic multilayers: Second-order magneto-optic effect in Ni/Cu bilayers and trilayers

The Brillouin light scattering technique has been exploited to detect spin waves in Ni/Cu bilayers and
trilayers deposited by RF sputtering. In order to reproduce the experimental results, a macroscopic partial
waves approach is used for the calculation of the normal modes, allowing the application of this model to
magnetic multilayered structures. The Brillouin cross section of the multilayer is calculated with the Green's
functions method, taking into account both first and second order magneto-optic effects ~Faraday and Voigt
effect, respectively!. By measuring Brillouin spectra for different applied fields we have determined the
magnetic parameters of the films as well as the ratio between the first and second order magneto-optic
constants.