Multimode Propagation of Magnetostatic Waves in a Width-Modulated Yttrium-Iron-Garnet Waveguide

An irregular tapered ferrite waveguide with a periodically width-modulated region was investigated. By using space- and time-resolved Brillouin light scattering spectroscopy, we measured the features of the intermodal interaction of width modes and their scattering at the boundaries of the waveguide. Near the band-gap frequency region, the spatial pattern of the spin-waves depends on the mode interaction in the periodically width-modulated yttrium-iron-garnet waveguide. These experimental results are important for controlling spin-wave propagation in width-modulated magnetic structures for future spintronic devices.