Preparation of Ce-substituted yttrium iron garnet films for magneto-optic waveguide devices

Ce-substituted yttrium iron garnet films are epitaxially grown in situ on (111)-oriented substrates of (Gd, Ca, Mg)(3)(Ga, Zr)(5)O-12 garnet by conventional rf diode sputtering for application to magneto-optic waveguide devices in optical communication systems. Pure argon or argon containing a small amount of oxygen is used as the sputter gas. After sputtering, the films are annealed in a nitrogen atmosphere. By optimizing this process, film propagation loss can be reduced while maintaining a large Faraday rotation. A propagation loss of 13 dB/cm and a Faraday rotation of -3900 degrees/cm have been obtained at a wavelength of 1.55 mu m.