In this thesis, wave effects associated with the refraction and reflection of plane, dipolar spin waves are investigated. All measurements are conducted with time-resolved scanning Kerr microscopy. This magneto-optical technique allows for imaging of phase-resolved magnetization dynamics in real space, thereby providing a direct access to wave characteristics: By fitting their interference pattern, wave vector, phase, and attenuation length can be quantified.
The anisotropic dispersion relation in the dipolar regime depends on the thickness of a ferromagnetic film. Therefore, a thickness step acts as a boundary between two media of different indices of refraction. In two related experiments, the refraction and reflection of spin waves at the interface between a thick Ni80Fe20 (Py) film and a thin Py film are investigated and Snell's law for spin waves is proven. In addition, the reflection of spin waves from an edge of a Py film is studied. There, the plane wave exhibits a phase shift reminiscent of the Goos-Hänchen shift.
All experiments provide valuable insight into the refraction and reflection of spin waves. Especially the study of refraction is interesting in the context of magnonics, where concepts to efficiently reduce wavelengths and steer spin waves are actively searched for. Besides these technological aspects, Snell's law and the Goos-Hänchen shift are fundamental wave effects which appear in various contexts throughout physics
