Multiple reflection effect on Co substituted Ba-Ferrite for magneto-optical recording media

We have studied the enhancement by mutiple reflection effect on Faraday rotation of Co-Ti-substituted BaM film which should be designed as thin as possible to reduce the laser power for magneto-optical recording and background noise caused by polycrystalline boundary. The sample constitution which is used in the experiment is Au reflective layer/Co-Ti-BaM magnetic layer/ Ni-Zn-ferrite under layer/quartz glass substrate. The multiple reflection effect was examined from the wavelength dependence of reflectivity and rotation. As the result, some enhanced peaks of the rotation of reflected light were observed. And the wavelengths at which they appeared exactly agreed with those at which, the reflectivity had bottoms. It was found that the Faraday rotation in infrared region was enhanced several times larger by multiple reflection.