Tm 3+–Ho 3+ and Tm 3+–Tb 3+ energy transfer in tellurite glass

Abstract

In Tm 3+–Ho 3+- and Tm 3+–Tb 3+-doped tellurite glasses, the IR fluorescence spectra and the lifetimes of the upper 3H 4 and lower 3F 4 lasing levels for 1.47 μm of Tm 3+ were measured. The non-exponential decay is fitted using the Inokuti–Hirayama equation. The energy-transfer parameter C DA, critical ion distance R 0, lifetime and non-radiative energy-transfer efficiency η between donor and acceptor ions are compared. The quenching mechanism has been explained. Both Ho 3+ and Tb 3+ ions reduce the lifetimes of the upper and lower lasing levels, with Tb 3+ ions proving more efficient than the effects observed for Ho 3+ ions. The optimised Tb 2O 3 concentration is about 1.0–1.5 wt%, which produced effective inversion and could be used for laser and amplifier applications.