Diffraction of light by a corrugated magnetic grating: Experimental results and calculation using a perturbation approximation to the Rayleigh method

When visible light is diffracted by a relief grating covered with a ferromagnetic film, the intensity diffracted in all orders varies as magnetization is reversed. The relative variation in diffracted intensity is measured in the transverse, but generally nonspecular, Kerr geometry (reflection case, magnetization perpendicular to diffraction plane). The effect is modelled using a perturbation approximation to the Rayleigh method. The theoretical results are in good agreement with experiment.