Faraday rotator single-crystals have attracted much attention in the field of magneto-optics due to their broad applications such as optical isolators, optical modulators, and beam splitters.  Rare-earth (RE) fluorides (CeF₃, PrF₃ and LiREF₄) single-crystals have been investigated due to their unique transmittance in the UV wavelength region.  The magneto-optical effects of the RE ions are known to be caused by the intraionic parity allowed electric dipole transition between the 4f^N and 4f^N-15d¹ configurations. These transitions are close to the absorption cut-off in the widely transparent fluorides, so that these achieve outstanding Verdet constants in the UV wavelength region. 

  Accurate Faraday rotation measurements have been carried out along the optical c-axis in order to avoid the linear birefringence.  However, to investigate the optical and magnetic properties of the RE fluorides in more detail, measurements along the perpendicular direction are required.  In this study, the wavelength dependences of the linear and circular birefringences of CeF₃ single-crystal along the a-axis were measured with the Generalized-High Accuracy Universal Polarimeter (G-HAUP).