Fabrication and characterizations of (Tb1-xPrx)3Al5O12 magneto-optical ceramics for Faraday isolators

Praseodymium doped terbium aluminum garnet (Pr:TAG) magneto-optical ceramics with different doping concentrations were fabricated by vacuum pre-sintering and hot isostatic pressing (HIP) post-treatment from the co-precipitated Pr:TAG nanopowders. It is found that all the as-synthesized powders exhibit a pure TAG phase and show good dispersity. The in-line transmittance of Pr:TAG ceramics fabricated by pre-sintering at 1700 °C for 20 h and HIP post-treating at 1700 °C for 3 h decreases from 80.6% to 76.3% at 1064 nm with the Pr3+ doping concentration increasing from 0 at% to 2.0 at%. The Verdet constant of the 2.0 at% Pr:TAG ceramics at 633 nm is −189.8 rad T-1 m-1, which is 42% larger than that of the commercial TGG single crystals (−134 rad T-1 m-1). The superior characteristics of the Pr:TAG ceramics indicate that they have great potential to meet the increasing requirements for magneto-optical devices used in the visible and near-infrared wavelength.