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Thin films with different compositions of Ce-substituted yttrium iron garnet (Ce:YIG (Y 2 CeFe 5 O 12 )), Ga-doped Ce:YIG (Ce:Ga:YIG (Y 2 CeFe 4.25 Ga 0.75 O 12 )), and Gd-doped Ce:YIG (Ce:Gd:YIG (Y 1.6 CeGd 0.4 Fe 5 O 12 )) were deposited on gadolinium gallium garnet (GGG (Gd 3 Ga 5 O 12 )) substrates in O 2 or Ar background gas by pulsed-laser deposition (PLD) technique. Crystalline films were obtained at a lower O 2 gas pressure of 20 mTorr or at higher Ar gas pressures of more than 100 mTorr. In addition, the behavior of YO molecules was visualized by two-dimensional laser-induced fluorescence (2D-LIF), in order to investigate the oxidation dynamics in the ablation plume. The oxidation dynamics and the crystallinity had close correlation.

In this paper, a new type of magnetic field optical sensor based on creation of the Faraday effect by rotation magnetization of Ce:YIG single crystals was studied. A large linear magnetic birefringence (LMB, the Cotton–Mouton effect) of Δn = −1.7 × 10−4 was observed in Ce:YIG crystal at the wavelength of 1.3 μm, and it was found that this effect is the main origin of the reduction of the sensitivity and its large temperature dependence. The validity of the method of utilizing a pair of Ce:YIG crystals with an azimuth angle of 90° in the optical axis is demonstrated as a method of improving these phenomena

The magnetooptical properties and magnetic-field-sensing properties of bulk Ce-substituted YIG (Ce x Y 3− x Fe 5 O 12 ) crystals were studied. There was an absorption edge at 1200 nm and a large negative Faraday rotation was obtained. Faraday rotation was increased to a greater extent by Ce substitution than by Bi substitution. The magnetic-field sensitivity of Ce 0.24 Y 2.76 Fe 5 O 12 was 0.0048% m/A which was larger than that of (BiGdLaY) 3 (FeGa) 5 O 12 . The optical current transformer (CT), using a Ce:YIG crystal as a sensor head, could measure the alternating steady state, faulting, breaking and reclosing currents. These results suggest that cerium-substituted yttrium iron garnet is a high-performance material suitable for magnetic-field (or electric-current) sensors.

Bi-doped yttrium iron garnet (Bi x Y 3− x Fe 5 O 12 , Bi:YIG) thin films, which can be used as electric current sensors, are grown on Gd 3 Ga 5 O 12 (GGG) substrates by pulsed laser deposition (PLD) using an ArF excimer laser. The growth condition for high quality epitaxial Bi:YIG thin films is investigated by varying the PLD process parameters, such as the substrate temperature and ambient oxygen gas pressure. The epitaxial film growth is attained at the substrate temperature of around 500 °C and at ambient oxygen pressure between 125 and 175 mTorr. The optical properties of epitaxial films are measured and the maximum magneto-optic sensitivity coefficient is observed to be 44.1°/T with a film thickness of about 0.7 μm at a wavelength of 500 nm. The results indicate that the PLD technique can be useful for realizing a miniature current sensing device with the Bi:YIG thin film.