Magneto-Optical Properties of Cerium-Substituted Yttrium Iron Garnet Single Crystals Grown by Traveling Solvent Floating Zone Method

A cerium-substituted yttrium iron garnet (Y 3- x Ce x Fe 5 O 12 ) single crystal was grown by the traveling solvent floating zone (TSFZ) method in an oxygen environment. Using a Fe- and Ce-rich solvent, high quality single crystals with smooth and lustrous surface were grown at a rate of 1.0 mm/h. The segregation coefficient of Ce was calculated approximately as 0.2 from the compositional profile in the grown crystals measured by electron probe X-ray microanalyzer (EPMA). The optical absorption coefficient and the Faraday rotation angle of Y 2.82 Ce 0.18 Fe 5 O 12 at 1550 nm wavelength were 0.12 cm -1 and -740 deg/cm, respectively. The figure of merit of a Faraday rotator was 1423 deg/dB. The absorption loss and sensitivity of the same Y 2.82 Ce 0.18 Fe 5 O 12 ( d =0.6 mm) for the magnetic field sensor were 0.03 dB and 0.1%/Oe, respectively, at 1550 nm wavelength. These results suggest that cerium-substituted yttrium iron garnet is a high performance material for the Faraday rotator at 1550 nm wavelength.