Spin Waves Focused Beams in YIG Films

Spin waves (SW) focused beams propagation and interference under excitation by curvilinear focusing transducers in tangentially magnetized yttrium iron garnet (YIG) films were studied using micromagnetic simulations and Mandelstam- Brillouin light scattering technique. It is shown that due to anisotropic SW propagation in tangentially magnetized films the two-dimensional maps of SW intensity exhibit nonreciprocal properties without mirror symmetry with respect to optic axis of the focusing transducers. Due to chromatic aberration and caustics formation of the focusing transducers, the interference pattern of the focused SW beams depends on excitation frequency and is sensitive to local nonuniformities in YIG film. The obtained results demonstrate possibility to use curvilinear SW focusing transducers for information technologies based on magnonic optics.