Magneto-optical properties of YIG single crystal by TSFZ method

The near infrared magneto-optical properties of the yttrium iron garnet single crystal (YIG) grown by the traveling solvent floating zone (TSFZ) method are presented in this paper. In fibre-optic communications YIG has been given attention as a magneto-optical and an optical nonreciprocal material. But there is little information about these properties for the available YIG. New data for YIG we developed are presented, including the absorption spectra, the Faraday rotation spectra, the magnetic field dependences of the extinction ratio and the refractive index spectrum, all in the near infrared. Typical results at 1.3 μm wavelength are (1) absorption coeff. α = 0.27/cm ( 2.0 mm thickness, transmissibility 94.7 % for AR-coated), (2) Faraday rotation ΘF= 222°/cm, (3) extinction ratio k = 2×10^-4. Regarding the application of YIG as an optical isolator, the temperature dependences of insertion loss (LF) and isolation (LB) were measured and at 1.3 μm wavelength, 20 °C, LF and LB were 1.4 dB and 33 dB, respectively.