Observation of 2.8 μm emission from diode-pumped Dy3+-doped fluoroaluminate glasses modified by TeO2

This work reports for the first time the observation of 2.8 μm emission in Dy3+ doped fluoroaluminate glasses modified by TeO2. The low phonon energy and large rare-earth ion solubility (>2 mol%) as well as the good thermal stability and transmission range up to >5 μm of fluoroaluminate-tellurite glasses, make them promising candidates for new mid-infrared solid-state laser host materials. The absorption and emission characteristics are investigated and the prepared glasses possess higher spontaneous transition probability (24 S−1) along with a larger calculated emission cross section (0.67×10−20 cm2) corresponding to the Dy3+: 6H13/2→6H15/2 transition. Intense emission around 2.8 μm is observed and the emission peak redshifts when >1 mol% rare earth ions are introduced into the glass network which can be explained by the self-absorption of Dy3+ ions. These results indicate that Dy3+-doped AlF3-based fluoroaluminate-tellurite glasses have potential applications in 2.8 μm laser materials.