Brillouin Light Scattering and Magnon Wave Vector Distributions for Microwave-Magnetic-Envelope Solitons in Yttrium-Iron-Garnet Thin Films

Brillouin light scattering has been used to measure wave number kₘ and wave vector kₘ angle distributions for 5 GHz magnetostatic backward-volume-wave envelope solitons in yttrium-iron-garnet thin films. For moderate powers, the data revealed spin waves directly associated with the solitons with kₘ values in the ±300rad/cm range. For high powers, the data showed high kₘ spin waves in the 2500--5000 rad/cm range with discrete in-plane kₘ directions at 90^∘{} and other angles around 90^∘{} relative to the soliton propagation direction. These high kₘ spin waves provide the first direct evidence of spin wave shedding associated with solitons at high powers.