Second order magneto-optic effects in Brillouin scattering from spin wavesin magnetic multilayers

The Brillouin light scattering cross section from a thick magnetic multilay er has been calculated using a theoretical model based on a macroscopic par tial waves approach for the calculation of the normal modes. Special attent ion has been paid to analyzing the effect of inclusion of the second order magneto-optic constant in addition to the first order one (corresponding to Voigt and Faraday effects, respectively). This model has been exploited to analyze the experimental Brillouin spectra measured from a several nm thic k Ni/Cu bilayer. Both surface and bulk standing spin waves have been experi mentally detected for different incident angles and applied magnetic fields (including field reversal). The measured spectra can be satisfactorily rep roduced by our model, allowing the determination of magnetic and magneto-op tic parameters of the samples. (C) 2001 American Institute of Physics.