A new type of magnet-optic media composed of ferromagnetic metal island films has been demonstrated for glass substrates. The optical loss of the ferromagnetic metal island films becomes much lower than that of conventional ultra-thin films with continuous structure in a wavelength region longer than the resonance wavelength, and a strong Faraday effect is kept in the island film. As the ferromagnetic metal island films can easily be fabricated on the glass and semiconductor substrates using a conventional vacuum evaporation method or a sputtering method, it is expected that will these become very useful media for optical devices.
