Effect of WO3 on physical and magneto-optical properties of TeO2–La2O3–WO3 glasses for magneto-optics application

Abstract

The ternary TeO2–La2O3–WO3 glasses with a formula of (100 − y − x)TeO2–yLa2O3–xWO3 (y = 5 and 10 mol%; x = 10 to 25 mol%) were made by the melting and casting method for high Verdet constant diamagnetic magneto-optical (MO) materials in the application of MO devices operating at 1550 nm. The compositional effects of WO3 and La2O3 contents on key glass properties of thermal stability, Knoop hardness, optical transmission, and Verdet constant, were systematically studied for both series of glasses. High transparency level (T: >70 %) in the region from 0.4 to 5.2 μm and a high refractive index (n: 2.05 at 1550 nm) were obtained in the studied glasses. The tellurite glasses with 5 mol% of La2O3 exhibited higher thermal stability and refractive indices than those with 10 mol% La2O3. The 85TeO2–5La2O3–10WO3 glass exhibited a large Verdet constant value of 3.95 rad/(T·m) at 1550 nm among the studied glasses. These results show that the presented TeO2–La2O3–WO3 glasses have considerable potential as diamagnetic MO materials for MO device applications operating at 1550 nm.