Transparent Tb3Fe5O12 ceramics as Mid-IR isolator

Fabrication of transparent TIG (Tb3Fe5O12) ceramics promising for 1.3-1.5 μm optical isolator was successful for the first time by a solid-state reaction between Tb4O7 and Fe2O3. The obtained TIG ceramics was free from grain boundary phases and inclusions but some residual pores were observed in the depth direction. Its in-line transmittance reached ca. 50% in infrared region of 1.1-2.0 μm. Faraday rotation angle of the TIG ceramics was 350deg./cm for 1300 nm, which is about 1.5 times larger than that of the YIG (Y3Fe5O12) single crystal. Removal of those residual pores can significantly improve optical properties.