Tailoring Near-Infrared Luminescence with Er3+/Tm3+/Yb3+ Tri-Doped Tellurite Glasses for Applications in the C, L and U Bands

In this work, co-doped and tri-doped systems with Er3+, Tm3+ and Yb3+ were evaluated in tungsten-tellurite glasses to extend the amplification range of current Erbium-Doped Fiber Amplifiers (EDFAs). The conditions of synthesis showed that the use of appropriate atmosphere was efficient to decrease the OH content and enhance the Er3+ emission. Spectroscopic studies on Er3+ and Tm3+ co-doped glasses revealed an emission from 1500 to 2000 nm with the energy transfer between both ions and the luminescence from Er3+: 4I(13/2) -> 4I(15/2) and Tm3+:3F(4) -> 4H(6). The addition of Yb3+ increased around 4 times in the NIR luminescence at 1535 nm. Lifetime measurements showed an increase of energy transfer efficiency (eta) from Er3+ to Tm3+ as Tm2O3 content increased. In addition, temperature-dependent luminescence is studied for co-doped and tri-doped systems in the range of-180 to 75 degrees C. As temperature decreases, the ratio between Er3+ and Tm3+ emissions increases whereas the introduction of Yb3+ considerably enhanced the emission from Er3+ at 1535 nm related to Tm3+. This study demonstrates that the NIR emission of these tellurite glasses, both in intensity and bandwidth, can be consid-erably tailored by means of the dopant content, synthesis conditions, and temperature.