Second harmonic generation in anisotropic magnetic-films - art. no. 184407

Nonlinear magneto-optical phenomena related to the process of second harmon ic generation in anisotropic films of different classes of symmetry are dis cussed. In the electric-dipole approximation two kinds of nonlinearity of c rystallographic and magnetic origin may coexist in noncentrosymmetric cryst als. The interference between the corresponding nonlinear optical waves res ults in novel magneto-optical effects, such as a transversal effect linear in magnetization at normal incidence and a circular magnetic asymmetry with no equivalence between light helicity and magnetization direction change. Epitaxial films of magnetic garnets grown on substrates with different crys tallographic orientations were taken as a model anisotropic system for expe rimental studies. The unambiguous separation of the crystallographic and ma gnetic contributions to the second harmonic generation is demonstrated with the help of rotational anisotropy experiments. A theoretical model for the nonlinear light propagation in noncentrosymmetric magnetic films is develo ped. Calculations based on this model are found to be in good agreement wit h the experimental results.