Spectroscopic properties of Yb3+/Tb3+ doped germanate glasses

Abstract

In the article the cooperative energy transfer in GeO2-GaO-BaO glass system doped with Yb3+/Tb3+ under 980 nm laser diode excitation was investigated. The influence of Tb3+ concentration on the luminescent properties was determined. Measured strong luminescence at 489, 543, 586, 621 corresponds to 5D4 → 7FJ (J = 6, 4, 3) transitions and luminescence at 381, 415, 435 nm results from 5D3, 5G6 → 7F J (J = 6, 5, 4) transitions. Mechanism and energy diagram involved in observed emission were discussed. The highest upconversion emission intensity was obtained in the germanate glass doped with 0.7 Yb2O 3/0.7 Tb2O3.