Diffraction-modified Kerr rotation from patterned garnet films

Bismuth-substituted yttrium iron garnet (Bi:YIG)-based two-dimensional (2D) magnetophotonic structures were fabricated on top of opal thin films. Autocloning approach was used to transpose 2D hexagonal symmetry of the opal (111) plane into sputtered Bi:YIG. Resultant 2D patterned Bi:YIG films had two realizations. As-sputtered films had a hemispherical profile of structural elements. These films were additionally etched to obtain films with a cone profile of scatterers. Optical and magneto-optical spectra of the films demonstrated resonances addressed to diffraction from the patterned Bi:YIG films. Structural parameters of these magneto-optical gratings were found to govern the magnitude of Kerr rotation.