Intense emission at 2.9 μm from Yb3+/Ho3+ co‐doped TeO2–Ga2O3–ZnO tellurite glasses

Abstract Mid‐infrared lasers have important applications in infrared countermeasures, sensing, environmental monitoring, biomedicine, and many military and civilian fields. In this work, an intense emission at 2.9 μm from Yb 3+ /Ho 3+ co‐doped TeO 2 ‐Ga 2 O 3 ‐ZnO (TGZ) glass was reported. The 2 μm, 1.2 μm and visible emissions were also performed to understand the competitive luminescent mechanism. With the increase in Yb 3+ concentration, all the emissions of Ho 3+ increased, whereas the emission of Yb 3+ decreased due to the phonon‐assisted energy transfer from Yb 3+ to Ho 3+ . The lifetimes of optimized 3 mol% Yb 2 O 3 and 1 mol% Ho 2 O 3 co‐doped TGZ glass, which has the maximum emission intensity, are 548 μs and 1.7 ms at 2.9 and 2 μm, respectively. The Judd–Ofelt intensity parameters, absorption, and emission cross sections were calculated to evaluate the mid‐infrared fluorescence properties of this new glass matrix material. The gain coefficients show that the 2 and 2.9 μm laser gain can be realized by small pump energy, indicating that this glass is a promising medium for the mid‐infrared optical fiber laser.