Transmission properties of multilayer films composed of magneto-optical and dielectric materials

In this paper, we investigated the transmission properties of multilayer films composed of magneto-optical and dielectric materials, in relation to layer stacking structure. The basic structures are made of alternating layers of these materials having a conventional symmetric periodicity with the center of the structure. Films with these basic structures exhibit an enhanced Faraday rotation effect. The rotation increases to an angle close to 45°, which is required for an optical isolator, as the repetition number of alternating layers increases. However, the transmittance decreases in these films as the rotation increases. To clarify the possibility of improving the transmittance, we also investigated films composed of multiple stacks of the basic structures. We found that, by using the multiple stacks, the transmittance can be improved without degrading the rotation characteristics