Hybridization‐Induced Spin‐Wave Transmission Stop Band within a 1D Diffraction Grating

Spin wave propagation is studied through a diffraction grating in a 200 nm thick YIG film by using scanning time resolved magneto‐optic Kerr microscopy (TR‐MOKE) and supported by micromagnetic simulations. Caustic‐like spin wave emission and the hybridization of Damon Eshbach (DE) type spin wave modes within the grating region, depending on the magnetic field and the dimensions of the grating, are observed. Hybridization leads to an increased attenuation length for propagating spin waves and consequently to a transmission stop‐band for spin waves at the grating for a certain magnetic field range. A simple design of a diffraction grating can act as a spin wave stop band for spin waves in the Damon Eshbach geometry if the total internal field is shifted to a value where hybridization between the Damon Eshbach mode and a standing spin wave mode occurs.