Magneto-Optical Properties of In-Plane Bi-YIG Films with Oblique-Incident Light

Because garnet film with an inplane orientation has no magnetization component parallel to perpendicularly incident light, no magnetooptic effects are observed when such light is incident. We supposed that when a Bi-YIG film is positioned obliquely to incident light, the plane of polarization would be rotated owing to the magnetooptic effect, because of the appearance of a magnetization component in the direction of the incident light. A Bi-YIG film with in-plane orientation was prepared on a Corning ¿ glass substrate by rf sputtering, and was then magnetized in a 2 kOe magnetic field. The apparatus for detecting Faraday rotation consisted of a polarization microscope and a light source. On the stage of the polarization microscope, the plane of the Bi-YIG film was tilted to 45° relative to the stage plane. The apparatus was used to obtain contrast images caused by the remanent magnetization of the in-plane-oriented Bi-YIG film. This result indicates that such in-plane magnetooptic films can be applied in display devices.