Preparation and Performance of Magneto-optical Glasses Doped with Tb3＋/Dy3

In order to increase the content of rare-earth oxides in magneto-optical glass and improve the Verdet constant, the rare-earth doped ternary Ga2O3-B2O3-SiO2（GBS） system magneto-optical glasses were prepared by the melt quenching technique. The infl uence of Tb3＋ and Dy3＋ ions on the structure of GBS glasses was investigated using FTIR, DSC and Faraday rotations. The experimental results showed that the content of rare-earth oxides in the glasses with the double incorporation of Tb2O3 and Dy2O3 was higher. The crystallization parameter β achieved the maximum 0.48 with Tb3＋/Dy3＋ content of 35mol%. Terbium oxide existed mainly in [TbO3] units in the glasses and [TbO4] units were converted into [TbO3] with increasing Tb2O3 content. As Ga3＋ ion is larger than B3＋ ion in radius, leading to an increasing of the glass network gap and improvement in the ability of accommodating rare earth ions, Verdet constant increased.