Luminescence properties of magneto-optical glasses containing Tb3+ ions

Abstract

Germanium borosilicate (GBS) magneto-optical glasses doped with terbium(Tb3+) ions with a chemical composition xTb2O3–10Ga2O3–20GeO2–30B2O3–50SiO2 (x = 20, 30, 40, 50, 60, 70 mol%)were prepared by a conventional melt quenching method and their physical properties, magneto-optical effect, luminescent properties were studied. The glasses show high optical basicity ranging from 0.582 to 0.685, and it was nearly a linear distribution of the optical basicity on the content of Tb2O3. The Verdet constant increases with increasing of the Tb2O3 concentration and glass containing 70 mol% Tb2O3 showed high Verdet constant (−0.5 min/Oe cm). Bright greenish-yellow luminescence was observed in all prepared glasses, which were generated mainly by the 5D4 → 7F6 emissions of Tb3+ ions. But the excitation, emission intensity and fluorescence lifetime of glasses drop with increasing of Tb2O3 for the concentration quenching of terbium ions. The large optical basicity causing by addition of Tb2O3 results in the increasing of Verdet constant for the energy separation of Tb3+ ions according to the Zeeman Effect. And it shortened the distance of rare earth ions and strengthened the cross-relaxation effects, which reduce the effective luminous intensity and lifetime of glasses. These Faraday rotation glasses containing Tb3+ ions are valuable materials for laser and magneto-optical devices.