Faraday Rotation Effect of Highly Tb₂O₃/Dy₂O₃-Concentrated B₂O₃−Ga₂O₃−SiO₂−P₂O₅ Glasses

A large amount of Tb2O3 and Dy2O3 has successfully been incorporated into a borate glass with a molar composition of 5B2O3−3Ga2O3−3SiO2−P2O5. Raman scattering analysis revealed the existence of isolated orthborate (BO3)3- groups with increasing rare-earth content. The obtained glass exhibited an excellent Faraday rotation effect in the visible region. The simultaneous incorporation of 40 mol % Tb2O3 and 10 mol % Dy2O3 offered the Verdet constant of as much as −185.3 rad/(T × m) at 632.8 nm at 300 K.