Kerr rotation enhancement in metallic bilayer thin films for magneto-optical recording

The enhancement of the magneto-optical Kerr effect via metallic bilayer structures is demonstrated for magneto-optic square loop materials on top of optically thick silver and copper reflectors, respectively. We show that in general an enhancement of the polar Kerr rotation angle θ/sub K/ occurs at photon energies where the optical constants n and k of the reflector have low values. The enhancement factor depends on the thickness of the magnetic layer and on the relative magnitude of the optical constants of both layers. The reflectivity of these bilayer structures is only slightly reduced compared to the bulk magneto-optical medium