Optimization of Y3Fe5O12 based layered structures for quasi-optic spin wave elements

We present theoretical and experimental results on the losses and confinement of spin waves (SW) in a Ferro- magnetic/Normal Metal/Air/Ferrite multilayer structure. The above structure can be used for the creation of a desired topology of static magnetic field in a thin ferrite film, used as SW waveguide. It is shown that a screening Normal Metal (NMe) layer, inserted between SW waveguide and ferromagnetic (FM) layer, significantly de- creases the SW losses caused by a lossy FM. It is also shown that the SW amplitude increases within the air gap (d) between a Ferrite film and NMe layer, when the gap satisfies the relation kd = 1, where k is SW wavenumber. The power flow density at Ferrite/Air interface is maximal when d is equal to a quarter wavelength of SW.